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1

Communicating the Excitement of Science  

ScienceCinema

In this talk (which will include some exciting science) I will discuss some lessons I have learned about communicating science to scientists (in my own field and others), students, the public, the press, and policy makers in giving 500+ colloquia and seminars, 300+ public lectures and many informal presentations (including cocktail parties).

Michael Turner

2010-01-08

2

Communicating the Excitement of Science  

SciTech Connect

In this talk (which will include some exciting science) I will discuss some lessons I have learned about communicating science to scientists (in my own field and others), students, the public, the press, and policy makers in giving 500+ colloquia and seminars, 300+ public lectures and many informal presentations (including cocktail parties).

Michael Turner

2009-06-05

3

RXTE Observations of Selected Blazars  

NASA Technical Reports Server (NTRS)

The work completed includes the analysis of observations obtained during Cycles 4 and 5 of the Rossi X-ray Timing Explorer (RXTE). The project is part of a longer-term, continuing program to study the X-ray emission process in blazars in collaboration with Dr. Ian McHardy (U. of Southampton, UK).

Marscher, Alan P.; Jorstad, Svetlana G.

2002-01-01

4

There's Nothing More Exciting than Science  

ERIC Educational Resources Information Center

The basic contention that a more imaginative, creative, and challenging approach will result in better achievement in SATs--in other words, if the children enjoy their science they will do better--was the basis of a project at Oxford Brookes University. The project was devised to encourage and enable the participating teachers to develop a…

Wilson, Helen; Mant, Jenny; Coates, David

2004-01-01

5

RXTE Observations of Selected Blazars  

NASA Technical Reports Server (NTRS)

The work completed includes the analysis of observations obtained during Cycles 4 and 5 of the Rossi X-ray Timing Explorer (RXTE). The project is part of a longer-term, continuing program to study the X-ray emission process in blazars in cooperation with Dr. Ian McHardy (U. of Southampton, UK). The goals of the program are to study the X-ray emission mechanism in blazars and the relation of the X-ray emission to changes in the relativistic jet. The program includes contemporaneous brightness and linear polarization monitoring at radio and optical wavelengths, total and polarized intensity imaging at 43 GHz with a resolution of 0.1 milliarcseconds with the Very Long Baseline Array (VLBA), and well-sampled X-ray light curves obtained from a series of approved RXTE programs.

Aller, Margo F.

2002-01-01

6

RXTE observations of Cas A  

Microsoft Academic Search

Rossi X-ray Timing Explorer (RXTE) observations of the bright supernova remnant Cas A have revealed a hard power law component above 10 keV in addition to two thermal components inferred from ASCA measurements of the many line centroids from low-Z elements. The power law can be shown to be consistent with synchrotron emission from radio to hard x-rays by electrons

R. E. Rothschild; R. E. Lingenfelter; P. R. Blanco; D. E. Gruber; W. A. Heindl; D. MacDonald; D. F. Marsden; M. R. Pelling; K. Jahoda; G. E. Allen; J. H. Swank; S. E. Woosley; K. Nomoto; J. C. Higdon

1999-01-01

7

INTEGRAL and RXTE Observations of Centaurus A.  

National Technical Information Service (NTIS)

INTEGRAL and RXTE performed three simultaneous observations of the nearby radio galaxy Centaurus A in 2003 March, 2004 January, and 2004 February with the goals of investigating the geometry and emission processes via the spectral/temporal variability of ...

R. E. Rothschild J. Wilms J. Tomsick R. Staubert S. Benlloch W. Collmar

2006-01-01

8

Beyond the Fizz: Getting Children Excited about Doing Real Science  

ERIC Educational Resources Information Center

The key to engaging children in doing real science is to understand the difference between a "science demonstration" and a "hands-on science experiment." Demonstrations performed by the teacher typically illustrate a science concept. But science experiments give children the opportunity to pose their own "What if . . . ?" questions, which…

Spangler, Steve

2009-01-01

9

INTEGRAL and RXTE Observations of Centaurus A  

SciTech Connect

INTEGRAL and RXTE performed three simultaneous observations of the nearby radio galaxy Centaurus A in 2003 March, 2004 January, and 2004 February with the goals of investigating the geometry and emission processes via the spectral/temporal variability of the X-ray/low energy gamma ray flux, and intercalibration of the INTEGRAL instruments with respect to those on RXTE. Cen A was detected by both sets of instruments from 3-240 keV. When combined with earlier archival RXTE results, we find the power law continuum flux and the line-of-sight column depth varied independently by 60% between 2000 January and 2003 March. Including the three archival RXTE observations, the iron line flux was essentially unchanging, and from this we conclude that the iron line emitting material is distant from the site of the continuum emission, and that the origin of the iron line flux is still an open question. Taking X-ray spectral measurements from satellite missions since 1970 into account, we discover a variability in the column depth between 1.0 x 10{sup 23} cm{sup -2} and 1.5 x 10{sup 23} cm{sup -2} separated by approximately 20 years, and suggest that variations in the edge of a warped accretion disk viewed nearly edge-on might be the cause. The INTEGRAL OSA 4.2 calibration of JEM-X, ISGRI, and SPI yields power law indices consistent with the RXTE PCA and HEXTE values, but the indices derived from ISGRI alone are about 0.2 greater. Significant systematics are the limiting factor for INTEGRAL spectral parameter determination.

Rothschild, Richard E.; /San Diego, CASS; Wilms, Joern; /Warwick U.; Tomsick, John; /San Diego, CASS; Staubert, Ruediger; Benlloch, Sara; /Tubingen U., IAAT; Collmar, Werner /Garching, Max Planck Inst., MPE; Madejski, Grzegorz; /SLAC; Deluit, Sandrine; /Toulouse, CESR; Khandrika, Harish; /La Jolla High School

2006-01-17

10

Monitoring the Galactic microquasars with RXTE  

Microsoft Academic Search

The Galactic microquasars GRS1915+105 and GRO J1655-40 were targets for dedicated monitoring programs with RXTE throughout 1996 and 1997. We review recent results with particular attention to the X-ray QPOs seen in these sources. We confirm the reappearance of 67Hz oscillations in GRS1915+105 in several different spectral states. Six intervals, each of 1 to 6 months duration, yield QPO detections

Ronald A. Remillard; Edward H. Morgan

1999-01-01

11

Monitoring the Galactic microquasars with RXTE  

Microsoft Academic Search

The Galactic microquasars GRS1915+105 and GRO J1655-40 were targets for dedicated monitoring programs with RXTE throughout 1996 and 1997. We review recent results with particular attention to the X-ray QPOs seen in these sources. We confirm the reappearance of 67 Hz oscillations in GRS1915+105 in several different spectral states. Six intervals, each of 1 to 6 months duration, yield QPO

Ronald A. Remillard; Edward H. Morgana

1999-01-01

12

RXTE observations of MXB 0656-072  

NASA Astrophysics Data System (ADS)

RXTE is currently performing a series of snapshot observations of the recurrent X-ray transient pulsar MXB 0656-072 (= XTE J0658-073), following the report of the detection of a new outburst of this source with INTEGRAL (ATEL #1281). Here we report on the detection of the source in the first two snapshot observations which were performed on 2007 November 14 (starting MJD 54418.233) and 2007 November 15 (starting MJD 54419.488).

Pottschmidt, K.; McBride, V. A.; Suchy, S.; Kreykenbohm, I.; Wilms, J.; Rothschild, R. E.; Kretschmar, P.; Schoenherr, G.; Caballero, I.; Kendziorra, E.; Staubert, R.; Swank, J. H.

2007-11-01

13

Improvements to the RXTE/PCA Calibration  

NASA Technical Reports Server (NTRS)

The author presents the current status of the RXTE/PCA Calibration, with emphasis on recent updates to the energy scale and the background subtraction. A new treatment of the Xenon K-escape line removes the largest remaining residual in the previously distributed matrices. Observations of Sco X-1 made simultaneously with Swift XRT, expressly for the purpose of cross calibrating the response to bright sources, are presented.

Jahoda, K.

2009-01-01

14

More Science Activities. 20 Exciting Experiments To Do!  

ERIC Educational Resources Information Center

Science and technology affect every facet of human life. By the 21st century, society will demand that all of its citizens possess basic competencies in the fundamentals of science and the use of technology. As science increasingly becomes the dominant subject of the work place, it is important to begin developing within children an understanding…

Smithsonian Institution, Washington, DC.

15

Still More Science Activities. 20 Exciting Activities To Do!  

ERIC Educational Resources Information Center

Science and technology affect every facet of human life. By the 21st century, society will demand that all of its citizens possess basic competencies in the fundamentals of science and the use of technology. As science increasingly becomes the dominant subject of the work place, it is important to begin developing within children an understanding…

Smithsonian Institution, Washington, DC.

16

Continued RXTE Observations of Three Blazars  

NASA Technical Reports Server (NTRS)

This project continued (during Cycle 3 of the RXTE mission) weekly observations of the quasars PKS 1510-089 and 3C 454.3 and the BL Lac object OJ 287. The data were analyzed by the PI and his graduate student. In the middle of Cycle 3, the PI changed the mode of observation of 3C 454.3, based on a report from another astronomer that observations with the Rosat satellite had found a strong confusing X-ray source about 45 arcmin away. The RXTE observations, in which the flux was measured while pointing directly at 3C 454.3 and then 15' from 3C 454.3, in the direction away from the confusing source. The flux decreased considerably, and so it appears that nearly all the X-ray flux measured by RXTE comes from the confusing source rather than the quasar. OJ 287 was detected only at one epoch of the Cycle 3 observations. This corresponded to a particularly quiet period for this source, when its flux at other wavebands was also low. From the single epoch of detection, no conclusions can be drawn concerning the general nature of the X-ray emission from this object. In contrast to the other two sources, the results of the observations of PKS 1510-089, when combined with data from cycles 3 and 4, are very interesting. The RXTE (2.4-20 keV) abd 14.5 GHz University of Michigan Radio Astronomy Observatory (UMRAO) light curves through the end of RXTE Cycle 4 are shown for PKS 1510-089. Visual inspection reveals an obvious correlation between the X-ray and 14.5 GHz light curves. While this is as expected in the SSC model in a source with simultaneous mm-wave (the photons thought to be scattered to X-ray energies) and cm-wave variations, the X-ray spectrum is flat ("energy" spectral index alpha = 0.2-0.5, where F (sub v) proportional to v (sup - alpha)) compared with the mm-wave synchrotron spectrum (alpha approximately equal to 0.8). The PI is currently engaged in theoretical work to determine whether this is possible for an SSC model.

Marscher, Alan P.

2000-01-01

17

RXTE Observations of Several Strong Flares from the TeV Blazar 1ES 1959+650  

NASA Technical Reports Server (NTRS)

Responding to the RXTE Cycle 7 NASA Research Announcement, we proposed to use the RXTE X-ray telescopes to intensively observe the TeV Gamma-ray Blazars Markarian 421, Markarian 501, 1ES 1959+650 and 1ES 1426+428, when their X-ray or TeV Gamma-ray fluxes would surpass preset trigger thresholds. In May and June, 2002, the Blazar 1ES 1959+650 (z=0.048) showed a series of spectacular X-ray and gamma-ray flares. Following the detection of a strong Gamma-ray flare on May 16 and 17 with the VERITAS 10 m Cherenkov Telescope, we invoked intensive RXTE observations, as well as complementary radio, optical and GeV/TeV Gamma-ray observations. From May 18 to August 14, more than 150 ksec RXTE observations were taken, yielding a unique data set with simultaneous RXTE and GeV/TeV Gamma-ray coverage.We used the financial support from the ADP program of NASA s Office for Space Science to perform a comprehensive analysis of the RXTE data. We studied in detail the temporal and spectral characteristics of the source. We collected multiwavelength data from a large number of collaborators, and performed a detailed cross-correlation analysis. Eventually, we interpreted the results in the framework of a Synchrotron-Self Compton model. The most important discovery of our research has been the detection of an orphan gamma-ray flare , not associated with an X-ray flare. The discovery showed conclusively that most models invoked to describe the non-thermal emission from blazars are overly simplistic.

Krawczynski, Henric

2004-01-01

18

X-Ray Pulsar Studies With RXTE  

NASA Technical Reports Server (NTRS)

Our activities here at MIT have largely concentrated on four different binary X-ray pulsars: LMC X-4; 4UO352+3O/XPer; 4U0115+63; and X1908+075. We have also recently initiated a search for millisecond X-ray pulsations in RXTE archival data for several bright LMXBs using a new technique. Since this study is just getting under way, we will not report any results here. Using RXTE timing observations of LMC X-4 we have definitively measured, for the first time, the orbital decay of this high-mass X-ray binary. The e-folding decay time scale is very close to lo6 years, comparable to, but somewhat longer than, the corresponding orbital decay times for SMC X-1 and Cen X-3. We find that the orbital decay in LMC X-4 is likely driven by tidal interactions, where the asynchronism between the orbital motion and the rotation of the companion star is maintained by the evolutionary expansion of the companion. Under NASA grant NAGS7479 we carried out RXTE observations of X Per/4U0352+30 in order to track the pulse phase over a one year interval. This effort was successful in tentatively identifying a N 250-day orbital period. However, due to the fact that the observing interval was only somewhat longer than the orbital period, we asked for the observations of X Per to continue as public, or non-proprietary observations. Dr. Jean Swank kindly agreed to the continuation of the observations and they were carried out on a less frequent basis over the next year and a half. After 72 separate observations of X Per, we have the orbital period and semimajor axis firmly determined. In addition, we were able to measure the orbital eccentricity-which turns out to be remarkably small (e = 0.10) for such a wide binary orbit. This has led us establish the birth of a neutron star with a very small (or zero) natal kick.

Rappaport, Saul

2004-01-01

19

Using Space Science to Excite Hispanic Students in STEM  

NASA Astrophysics Data System (ADS)

Over the past ten years, NASA and its cosponsors have held an annual "NASA Space Science Day" at the University of Texas at Brownsville. The event is held over two days, with the Friday evening program featuring a space scientist or astronaut, this year Joe Acaba, giving a public lecture (plus a free planetarium show). The Saturday event starts with a keynote speech from the same speaker. Then the students circulate among six or seven hands-on workshops, plus a scheduled trip to the "Demo room" where NASA missions show their materials, and a planetarium show in the Discovery Dome. The students, 4th through 8th graders, are drawn from schools all across south Texas, and have included students coming as far as Zapata, with a four-hour bus ride each way. Over the ten years of the program, more than 5000 students have been reached. Most of the hands-on activities are led by undergraduate student mentors. The university students (42 in 2013) received science and engineering content and mentor training on the activities at Johnson Space Center before the January event. In addition, an additional 40 local high school students helped with activities and with escorting each group of students from one activity station to the next. The program has been so successful that students have "graduated" from participant, to volunteer, and now to University student mentor. Most of the mentors go on to complete a degree in a STEM discipline, and many have gone on to graduate school. Thus the mentors not only help with the program, they are beneficiaries as well. The program is being expanded to reach other underserved communities around the US, with its first "expansion" event held in Utah in 2011.; Puerto Rican Astronaut Joe Acaba and the Discovery Dome were two of the highlights for the students.

Reiff, P. H.; Galindo, C.; Garcia, J.; Morris, P. A.; Allen, J. S.

2013-05-01

20

Absolute Timing of the Crab Pulsar with RXTE  

Microsoft Academic Search

We have monitored the phase of the main X-ray pulse of the Crab pulsar with\\u000athe Rossi X-ray Timing Explorer (RXTE) for almost eight years, since the start\\u000aof the mission in January 1996. The absolute time of RXTE's clock is\\u000asufficiently accurate to allow this phase to be compared directly with the\\u000aradio profile. Our monitoring observations of the

Arnold H. Rots; Keith Jahoda; Andrew G. Lyne

2004-01-01

21

RXTE Standard Data Products: Archival Observations at a Glance  

NASA Astrophysics Data System (ADS)

The RXTE GOF has designed a set of standard data products that are currently being produced for archival observations. As the RXTE mission matures, the archive of high quality data on individual objects and classes of objects is becoming increasingly fruitful to researchers. Standard data products allow the user to get a quick overview of an archival observation. Light curves, spectra and other high-level products created from generic analysis of standard-mode data reveal the amount of good time, PCA and HEXTE count rates, (source, background, and net), spectral hardness, and any sudden changes in brightness (flares or eclipses). The archive contains the product files themselves (in FITS format) as well as .gif images for a number of key plots to facilitate browsing of the data products. The standard data products are not meant to take the place of careful data analysis by the user; rather, they offer a glimpse of the quality and details of archival observations. Standard data products have so far been produced for all archival RXTE observations from the first three years of RXTE operations, and are currently available in the RXTE Archive. We continue to generate standard products for later data. It is our goal to eventually include the new standard products with all new data deliveries.

Boyd, P. T.; Tripicco, M. J.; Smale, A. P.; Kiddy, A. C.; Rohrbach, G. L.; RXTE Guest Observer Facility GOF Team

2001-12-01

22

Using the Process and Excitement of Science and Technology to Empower Teachers and Engage their Students  

NASA Astrophysics Data System (ADS)

Students United with NASA Becoming Enthusiastic About Math and Science (SUNBEAMS) is a Partnership between NASA Goddard Space Flight Center (GSFC) and the District of Columbia Public Schools (DCPS). It empowers teachers and inspires students with the process and excitement of science and technology. SUNBEAMS is being developed as a model urban intervention program for sixth grade teachers and their students. The teachers come to Goddard for five weeks during the summer. They partner with Goddard mentors and work much the same way that summer students do. In addition, the teachers are responsible for developing lesson plans that they pilot at their schools and post on the SUNBEAMS web site. During the school year, each teacher brings one class to Goddard for a full week of total immersion in math and science.

Crannell, C. J.

2002-06-01

23

Using the Process and Excitement of Science and Technology to Empower Teachers and Engage their Students  

NASA Technical Reports Server (NTRS)

Students United with NASA Becoming Enthusiastic About Math and Science (SUNBEAMS) is a Partnership between NASA Goddard Space Flight Center (GSFC) and the District of Columbia Public Schools (DCPS). It empowers teachers and inspires students with the process and excitement of science and technology. SUNBEAMS is being developed as a model urban intervention program for sixth grade teachers and their students. The teachers come to Goddard for five weeks during the summer. They partner with Goddard mentors and work much the same way that summer students do. In addition, the teachers are responsible for developing lesson plans that they pilot at their schools and post on the SUNBEAMS web site. During the school year, each teacher brings one class to Goddard for a full week of total immersion in math and science.

Crannell, Carol Jo

2002-01-01

24

Low-mass X-ray Binaries with RXTE  

NASA Technical Reports Server (NTRS)

Below are the publications which directly and indirectly evolved from this very successful program: 1) 'Search for millisecond periodicities in type I X-ray bursts of the Rapid Burster'; 2) 'High-Frequency QPOs in the 2000 Outburst of the Galactic Microquasar XTE J1550-564'; 3) 'Chandra and RXTE Spectroscopy of Galactic Microquasar XTE 51550-564 in Outburst'; 4) 'GX 339-4: back to life'; 5) 'Evidence for black hole spin in GX 339-4: XMM-Newton EPIC-PN and RXTE spectroscopy of the very high state'.

2004-01-01

25

Simultaneous INTEGRAL/RXTE Observations of GRS 1915+105  

NASA Astrophysics Data System (ADS)

We present the first results of simultaneous INTEGRAL and RXTE observations of the microquasar GRS 1915+105. We focus on the analysis of the unique highly variable observation and show that we might have observed a new class of variability. We then study the energetic dependence of a low frequency QPO from our steady observations.

Rodriguez, J.; Hannikainen, D. C.; Vilhu, O.; Fuchs, Y.; Shaw, S. E.

2004-07-01

26

"XMM/RXTE Observations of GX 339-4"  

NASA Technical Reports Server (NTRS)

In March 2003, we performed two simultaneous XMM/RXTE observations of the black hole candidate GX 339-4. Our goal is to compare these data to our prior simultaneous RXTE/ASCA observations (Nowak, Wilms & Dove, 2002). These observations were carried out in timing mode, as opposed to burst mode, and are more complex to analyze than we expected. Specifically, the data suffered from a number of telemetry dropouts (in fact, the standard archive processing failed on these data, and more than a year passed from the time of the observations before the data was delivered to us). Furthermore, the core of the EPIC PSF suffers slightly from pileup and gain shifts. We continue to work on this data, however, and anticipate publishing it within the next academic year. Here we highlight our ongoing work and outline our plans for publication.

Nowak, M. A.; Corbel, S.; Fender, R.; Wilms, J.; Kuster, M.; Bailyn, C.; Coppi, P.

2005-01-01

27

Bat Triggered Target of Opportunity Observations with RXTE  

NASA Astrophysics Data System (ADS)

We propose to trigger RXTE PCA observations of new galactic sources discovered as part of the Hard X-ray Transient Monitor of the Burst Alert Telescope (BAT) on the Swift satellite. BAT can provide an early hard X-ray (15-50 keV) trigger on a moderately bright new source. We need the complementary high sensitivity timing data from RXTE to distinguish between various models for the origin of the new transient. By studying the temporal properties of the source in the early turn-on phase we can distinguish between the early accretion disk flow of a black hole candidate, and the periodic emission from a millisecond pulsar or longer period pulsar. This will allow us to rapidly identify the source class and to publish results from the turn-on phase of newly discovered galactic transients.

Krimm, Hans

28

Chasing Superbursts with RXTE, Swift\\/bat and Integral (ibas)  

Microsoft Academic Search

We propose to carry out high throughput studies of superbursts with RXTE based on real-time triggers provided by the ASM, the Burst Alert Telescope (BAT) onboard the SWIFT gamma-ray burst mission and\\/or the INTEGRAL burst alert system (IBAS). We will use spectroscopy to probe the accretion disk and will search for millisecond pulsations in order to find spin periods and

Tod Strohmayer

2007-01-01

29

RXTE Observations of LMC X-1 and LMC X-3  

NASA Technical Reports Server (NTRS)

Of all known persistent stellar-mass black hole candidates, only LMC X-1 and LMC X-3 consistently show spectra that are dominated by a soft, thermal component. We present results from long (170 ksec) Rossi X-ray Timing Explorer (RXTE) observations of LMC X-1 and LMC X-3 made in 1996 December. The spectra can be described by a multicolor disk blackbody plus an additional high-energy power-law. Even though the spectra are very soft (Gamma approximately 2.5), RXTE detected a significant signal from LMC X-3 up to energies of 50 keV, the hardest energy at which the object was ever detected. Focusing on LMC X-3 , we present results from the first year of an ongoing monitoring campaign with RXTE which started in 1997 January. We show that the appearance of the object changes considerably over its approximately 200 d long cycle. This variability can either be explained by periodic changes in the mass transfer rate or by a precessing accretion disk analogous to Her X-1.

Wilms, J.; Nowak, M. A.; Dove, J. B.; Pottschmidt, K.; Heindl, W. A.; Begelman, M. C.; Staubert, R.

1999-01-01

30

RXTE Observations of LMC X-1 and LMC X-3  

NASA Technical Reports Server (NTRS)

Of all known persistent stellar-mass black hole candidates, only LMC X-1 and LMC X-3 consistently show spectra that are dominated by a soft, thermal component. We present results from long (170 ksec) Rossi X-ray Timing Explorer (RXTE) observations of LMC X-1 and LMC X-3 made in 1996 December. The spectra can be described by a multicolor disk blackbody plus an additional high-energy power-law. Even though the spectra are very soft (Gamma approximately 2.5), RXTE detected a significant signal from LMC X-3 up to energies of 50 keV, the hardest energy at which the object was ever detected. Focusing on LMC X-3, we present results from the first year of an ongoing monitoring campaign with RXTE which started in 1997 January. We show that the appearance of the object changes considerably over its approximately 200d long cycle. This variability can either be explained by periodic changes in the mass transfer rate or by a precessing accretion disk analogous to Her X-1.

Wilms, J.; Nowak, M. A.; Dove, J. B.; Pottschmidt, K.; Heindl, W. A.; Begelman, M. C.; Staubert, R.

1998-01-01

31

Echo Tomography of Hercules X-1: Mapping the Accretion Disc with RXTE and HST  

NASA Technical Reports Server (NTRS)

A paper based on the RXTE results contents the following and are ready for submission to ApJ: "Possible Detection of Companion Star Reflection from Hercules X-1 with RXTE". A paper combining July 1998 and July 1999 observations (including the RXTE results for both years) is nearly ready for submission to ApJ: The July 1998 and July 1999 Multiwavelength Campaigns on Hercules X-I/HZ Herculis. The July 1999 observations took place during an anomalous X-ray low state and the RXTE and EUVE data are consistent with X_ray reflected from the surface of the companion star.

Vrtilek, S.

2000-01-01

32

RXTE and VLA Observations of the Unique Atoll Sources 4u 1820-30 & 4u 1728-34: Probing Inflow and Outflow  

NASA Astrophysics Data System (ADS)

Radio emission phenomena in low mass X-ray binaries (LMXBs) include exciting effects such as relativistic outflows from the black hole candidates (BHCs; e.g. GRS 1915+105) and clear disk : jet coupling (e.g. GX 339-4). The power required to drive this radio emission is enormous (~50% of accretion luminosity). Atoll sources are observationally similar in many ways to BHCs. Physically this may result from a comparable population of energetic electrons. As a result two processes occur, Comptonisation, leading to the high-energy X-rays observed, and synchrotron emission, observable at radio wavelengths. After our succesfull RXTE/VLA campain on 4U 1728-34 in AO5 we propose correlated RXTE/VLA observations of both 4U 1728-34 and 4U 1820-30 designed to disentangle the X-ray/radio connections.

Fender, Robert

33

Observations of some x-ray transients with RXTE  

NASA Astrophysics Data System (ADS)

We present results of observations of several X-ray transients with RXTE in 1996-1998, namely, GRS 1739-278, XTE J1748-288, GS 1354-64, 2S1803-245 and XTE J0421+560 (CI Cam). We studied light curves and spectra of their outbursts and compared them with observations of other X-ray transients. We discuss fits of high state spectra with BMC model, and similarities and differences between black holes and neutron stars in their low state. Special attention is paid to CI Cam as possible legate for new class of X-ray transients.

Borozdin, K.; Priedhorsky, W.

1999-11-01

34

Observations of some X-ray transients with RXTE  

NASA Astrophysics Data System (ADS)

We present results of observations of several X-ray transients with RXTE in 1996-1998, namely, GRS 1739-278, XTE J1748-288, GS 1354-64. 2S1803-245 and XTE J0421+560 (CI Cam). We studied light curves and spectra of their outbursts and compared them with observations of other X-ray transients. We discuss fits of high state spectra with BMC model, and similarities and differences between black holes and neutron stars in their low state. Special attention is paid to CI Cam as possible legate for new class of X-ray transients. .

Borozdin, Konstantin N.; Priedhorsky, William C.; Revnivtsev, Mikhail G.; Emelyanov, Artem N.; Trudolyubov, Sergey P.; Titarchuk, Lev G.; Vikhlinin, Alexey A.

2000-04-01

35

The RXTE All Sky Monitor: First Year of Performance  

NASA Astrophysics Data System (ADS)

The first year of the RXTE ASM is reviewed from both programmatic and scientific perspectives. The difficulties in providing regular sampling rates for X-ray sources include the problems of solar avoidance and the large regions with enhanced (damaging) particle background in the RXTE orbit. Methods for minimizing the effects of source confusion in the galactic center are described. The advantages of supplemental data modes for instrument timing and spectral information are illustrated in the case of GRS1915+105. Highlights from the ASM results include the detection of X-ray outbursts from GROJ1655-40, 4U1630-47, and the Rapid Burster, as well as the detection of changes in the X-ray emission states of Cyg X-1 and GRS1915+105. The ASM light curves show periodic and quasiperiodic behavior from many X-ray sources, and the source histories provide a context that can be crucial in evaluating the timing and spectral results from brief observations with larger instruments.

Remillard, R. A.; Levine, A. M.

36

RXTE Monitoring and ``Imaging" Observations of the Galactic Bulge  

NASA Astrophysics Data System (ADS)

We present results from RXTE monitoring observations of the galactic center. RXTE has performed a raster scan of a rectangular region approximately 16o X 18o surrounding the galactic center on a twice weekly basis from February 1999 to the present, except for sun avoidance regions. In addition to the known X-ray sources, of which we detect about 30, we have found 7 new sources, which range in intensity from 1--60 mCrab. Some of the new sources are highly variable on time scales ranging from minutes to days, with amplitudes as high as 50% RMS. One previously unknown source, XTE J1819-254, was weakly active (< 10 mCrab) for seven months before exhibiting a 10 Crab outburst in September 1999. In follow-up observations of one new source, XTE J1710-281 there is evidence for eclipsing, dipping and burst acivity. We present monitoring light curves for a selection of these sources.

Markwardt, C. B.; Swank, J. H.; Marshall, F. E.; in't Zand, J. J. M.

37

XTE Observations of Intermediate Polars: RXTE TOO Observations of Supernovae  

NASA Technical Reports Server (NTRS)

Two intermediate polar cataclysmic variables, PQ Gem and AO Psc, were observed jointly with the Rossi X-ray Timing Explorer (RXTE) and ground-based photometry. The analysis of intermediate polars (IPs) is complex because these objects exhibit light curves that behave differently as a function of energy and that behave differently when phased on the orbital or on the spin periods. The presence of two periods in one system is essentially equivalent to analyzing two different X-ray sources. A preliminary analysis of the PQ Gem data was carried out and presented at the Annapolis Workshop on Magnetic Cataclysmic Variables. The final analysis of the data were held up by problems with the background estimation. The RXTE PCA team has released a new version of the background estimator. The PQ Gem must be reanalyzed using the new background. We have also installed a spectral model that calculates the expected emission from an accretion column. That model is undergoing final testing before we apply it to the data.

Schlegel, E.; Swank, Jean (Technical Monitor)

2002-01-01

38

The Excitement and Wonder of Teaching Science: What Pre-Service Teachers Learn from Facilitating Family Science Night Centers  

ERIC Educational Resources Information Center

In this study, pre-service teachers facilitated stations at a family science night as a context to learn to identify, assess, and use children's science ideas. Assessment is already difficult in K-12 classrooms. Assessing learning in informal learning environments adds the complication that participation is largely voluntary. As such, controlling…

Harlow, Danielle B.

2012-01-01

39

The Excitement and Wonder of Teaching Science: What Pre-service Teachers Learn from Facilitating Family Science Night Centers  

NASA Astrophysics Data System (ADS)

In this study, pre-service teachers facilitated stations at a family science night as a context to learn to identify, assess, and use children's science ideas. Assessment is already difficult in K-12 classrooms. Assessing learning in informal learning environments adds the complication that participation is largely voluntary. As such, controlling the learners' participation to systematically assess learning is counter to the intents of informal environments. The pre-service teachers in this study experienced success at teaching science and developed understandings about children's science ideas. Data included reflective postings, class discussions, observations, artifacts, and photographs. The findings contribute to understanding the value of multiple learning contexts in teacher preparation and lead to implications about leveraging informal science contexts for educating teachers.

Harlow, Danielle B.

2012-02-01

40

Analysis of RXTE data on Clusters of Galaxies  

NASA Technical Reports Server (NTRS)

This grant provided support for the reduction, analysis and interpretation of of hard X-ray (HXR, for short) observations of the cluster of galaxies RXJO658--5557 scheduled for the week of August 23, 2002 under the RXTE Cycle 7 program (PI Vahe Petrosian, Obs. ID 70165). The goal of the observation was to search for and characterize the shape of the HXR component beyond the well established thermal soft X-ray (SXR) component. Such hard components have been detected in several nearby clusters. distant cluster would provide information on the characteristics of this radiation at a different epoch in the evolution of the imiverse and shed light on its origin. We (Petrosian, 2001) have argued that thermal bremsstrahlung, as proposed earlier, cannot be the mechanism for the production of the HXRs and that the most likely mechanism is Compton upscattering of the cosmic microwave radiation by relativistic electrons which are known to be present in the clusters and be responsible for the observed radio emission. Based on this picture we estimated that this cluster, in spite of its relatively large distance, will have HXR signal comparable to the other nearby ones. The planned observation of a relatively The proposed RXTE observations were carried out and the data have been analyzed. We detect a hard X-ray tail in the spectrum of this cluster with a flux very nearly equal to our predicted value. This has strengthen the case for the Compton scattering model. We intend the data obtained via this observation to be a part of a larger data set. We have identified other clusters of galaxies (in archival RXTE and other instrument data sets) with sufficiently high quality data where we can search for and measure (or at least put meaningful limits) on the strength of the hard component. With these studies we expect to clarify the mechanism for acceleration of particles in the intercluster medium and provide guidance for future observations of this intriguing phenomenon by instrument on GLAST. The details of the nonthermal particle population has important implications for the theories of cluster formation, mergers and evolution. The results of this work were first presented at the High Energy Division meeting of the American astronomical Society at Mt. Tremblene, Canada (Petrosian et al. 2003). and in an invited review talk at the General Assembly of the International Astronomical Union at Sydney, Australia (Petrosian, 2003). A paper describe the observations, the data analysis and its implication is being prepared for publication in the Astrophysical Journal.

Petrosian, Vahe

2004-01-01

41

Absolute Timing of the Crab Pulsar with RXTE  

NASA Technical Reports Server (NTRS)

We have monitored the phase of the main X-ray pulse of the Crab pulsar with the Rossi X-ray Timing Explorer (RXTE) for almost eight years, since the start of the mission in January 1996. The absolute time of RXTE's clock is sufficiently accurate to allow this phase to be compared directly with the radio profile. Our monitoring observations of the pulsar took place bi-weekly (during the periods when it was at least 30 degrees from the Sun) and we correlated the data with radio timing ephemerides derived from observations made at Jodrell Bank. We have determined the phase of the X-ray main pulse for each observation with a typical error in the individual data points of 50 microseconds. The total ensemble is consistent with a phase that is constant over the monitoring period, with the X-ray pulse leading the radio pulse by 0.01025 plus or minus 0.00120 period in phase, or 344 plus or minus 40 microseconds in time. The error estimate is dominated by a systematic error of 40 microseconds, most likely constant, arising from uncertainties in the instrumental calibration of the radio data. The statistical error is 0.00015 period, or 5 microseconds. The separation of the main pulse and interpulse appears to be unchanging at time scales of a year or less, with an average value of 0.4001 plus or minus 0.0002 period. There is no apparent variation in these values with energy over the 2-30 keV range. The lag between the radio and X-ray pulses ma be constant in phase (i.e., rotational in nature) or constant in time (i.e., due to a pathlength difference). We are not (yet) able to distinguish between these two interpretations.

Rots, Arnold H.; Jahoda, Keith; Lyne, Andrew G.

2004-01-01

42

Extending RXTE Coverage of CEN a during the Integral Multi-Wavelength Campaign  

NASA Astrophysics Data System (ADS)

We request an additional 160 ks of observing time on Cen A with RXTE in mid-January, 2009 to early-February, 2009 in order to increase our present Cen A time (~40 ks) to 200 ks. This will allow RXTE to monitor as fully as practical the 600 ks INTEGRAL observation. The INTEGRAL observation is the basis for our multi-wavelength campaign from radio to GeV energies. The high RXTE sensitivity to daily variability in Cen A will be extremely valuable in interpreting the activity state of the system during the longer INTEGRAL observation. We will compare RXTE data to that taken at 8.4 and 22 GHZ by the TANAMI program of densely sampled VLBI monitoring of the nuclear jet. From this and the multi- wavelength SED we will test nuclear jet models.

Rothschild, Richard

43

Life in the Universe: Foundation for exciting multidisciplinary science activities for middle and elementary school classes  

NASA Technical Reports Server (NTRS)

Young students find extra-terrestrial life one of the most intriguing of all topics. A project funded by the National Science Foundation and NASA, and administered by the SETI Institute, is underway to devise science lessons for grades 3-9 that draw upon this fascination. The lessons are designed by teachers and persons with long experience at curriculum design, tested in classrooms, revised and retested. Six guides, each containing some 6-10 science lessons, will be finished by summer, 1994.The theme Life in the Universe lends itself naturally to integrated treatment of facts and concepts from many scientific disciplines. The lessons for two completed guides span the origin of planet systems, evolution of complex life, chemical makeup of life, astronomy, spectroscopy, continental drift, mathematics and SETI (Search for Extra-Terrestrial Intelligence). All lessons are hands-on, interesting, and successful.

Milne, D.; O'Sullivan, K.

1994-01-01

44

Advances in the RXTE Proportional Counter Array Calibration: Nearing the Statistical Limit  

NASA Technical Reports Server (NTRS)

During its 16 years of service Rossi X-ray Timing Explorer (RXTE) mission has provided an extensive archive of data, which will serve as a primary source of high cadence observation of variable X-ray sources for fast timing studies. It is, therefore, very important to have the most reliable calibration of RXTE instruments. The Proportional Counter Array (PCA) is the primary instrument on-board RXTE which provides data in 2-50 keY with higher than millisecond time resolution in up to 256 energy channels. In 2009 RXTE team revised the response residual minimization method used to derive the parameters of the PCA physical model. The procedure is now based on the residual minimization between the model spectrum for Crab nebula emission and a calibration data set consisting of a number of spectra from the Crab and the on-board Am241 calibration source, uniformly covering a whole RXTE span. The new method led to a much more effective model convergence and allowed for better understanding of the behavior of the PCA energy-to-channel relationship. It greatly improved the response matrix performance. We describe the new version of the RXTE/PCA response generator PCARMF vll.7 along with the corresponding energy-to-channel conversion table (version e05v04) and their difference from the previous releases of PCA calibration. The new PCA response adequately represents the spectrum of the calibration sources and successfully predicts the energy of the narrow iron emission line in Cas-A throughout the RXTE mission.

Shaposhnikov, Nikolai; Jahoda, Keith; Markwardt, Craig; Swank, Jean; Strohmayer, Tod

2012-01-01

45

Advances in the RXTE Proportional Counter Array Calibration: Nearing the Statistical Limit  

NASA Astrophysics Data System (ADS)

During its 16 years of service, the Rossi X-Ray Timing Explorer (RXTE) mission has provided an extensive archive of data, which will serve as a primary source of high cadence observations of variable X-ray sources for fast timing studies. It is, therefore, very important to have the most reliable calibration of RXTE instruments. The Proportional Counter Array (PCA) is the primary instrument on board RXTE which provides data in 3-50 keV energy range with submillisecond time resolution in up to 256 energy channels. In 2009, the RXTE team revised the response residual minimization method used to derive the parameters of the PCA physical model. The procedure is based on the residual minimization between the model spectrum for Crab Nebula emission and a calibration data set consisting of a number of spectra from the Crab and the on-board Am241 calibration source, uniformly covering the whole RXTE mission operation period. The new method led to a much more effective model convergence and allowed for better understanding of the PCA energy-to-channel relationship. It greatly improved the response matrix performance. We describe the new version of the RXTE/PCA response generator PCARMF v11.7 (HEASOFT Release 6.7) along with the corresponding energy-to-channel conversion table (version e05v04) and their difference from the previous releases of PCA calibration. The new PCA response adequately represents the spectrum of the calibration sources and successfully predicts the energy of the narrow iron emission line in Cas-A throughout the RXTE mission.

Shaposhnikov, Nikolai; Jahoda, Keith; Markwardt, Craig; Swank, Jean; Strohmayer, Tod

2012-10-01

46

Simultaneous RXTE and High Resolution Spectroscopy of a Black Hole Transient  

NASA Astrophysics Data System (ADS)

High resolution spectra of Galactic black hole transients observed with Chandra and XMM-Newton have revealed relativistic iron disk lines. These lines are extremely powerful diagnostics of the inner accretion flow, as they can be used to constrain black hole spin without knowledge of the black hole mass or distance. However, simultaneous broad-band RXTE spectroscopy is essential to accurately determining the continuum spectrum underneath the line. It is only with RXTE spectra that self-consistent models of disk reflection (of which the iron line is merely a part) can be reliably constrained. We request up to 200 ksec of RXTE time to obtain essential simultaneous broad-band spectra, as part of a larger global simultaneous multi-wavelength program including Chandra and XMM-Newton.

Miller, Jon

47

Coordinated VLA, Optical, EUVE, and RXTE Monitoring of Flares on EQ Pegasi and AU Microscopii  

NASA Astrophysics Data System (ADS)

We present initial results from coordinated, multi-wavelength monitoring of two nearby dMe flare stars: EQ Pegasi and AU Microscopii. Our primary goal was to observe the impulsive and cooling phases of stellar flares. AU Mic was observed 1996 June 12-15 with the RXTE and EUVE satellites. EQ Peg was observed 1996 October 2-6 with RXTE, EUVE, the ubvr photometer on the McDonald Observatory 0.9-m telescope, and the VLA at 3.5 and 20 cm. We present light curves in most observed wavebands and X-ray spectra obtained during flares and quiescence. Although a number of moderately polarized VLA radio flares are seen, there is no compelling evidence in the RXTE data for hard, non-thermal X-ray emission. We also discuss an extreme ultraviolet transient event detected by ALEXIS on 1996 June 15 in the direction of AU Mic.

Gagne, Marc; Valenti, Jeff; Johns-Krull, Christopher; Linsky, Jeffrey; Brown, Alex; Gudel, Manuel

48

The Radio Counterparts of X-ray Transients Discovered by RXTE  

NASA Astrophysics Data System (ADS)

Events in eleven X-ray transient observed in detail by the RXTE produced radio counterparts. This includes four Galactic superluminal sources or microquasars: GRS 1915+105, which had many events between 1996 and 2000; the 1996-1997 event in GRO J1655-40; XTE J1748-288, the first Galactic superluminal discovered by RXTE in 1998; and the Sep. 14-16 events in V4641 Sgr (=XTE J1819-254), the closest microquasar at a probable distance of 0.5 kpc. In addition, the recurrent BHC transient 4U 1630-47 had an event with a radio counterpart in 1998, as did five other X-ray transients first discovered by RXTE: CI Cam (=XTE J0421+560), XTE J1550-564, XTE J1739-278, XTE J1806-246, XTE J1859+226, and XTE J2012+381. In this paper we summarize what is known about the relationship between the X-ray and radio events in these objects, including the radio images for the two microquasars discovered by RXTE, and CI Cam, a system that produced initial, fast jets but was later dominated by a slowly, 1000 km/sec, expanding remnant.

Hjellming, R. M.; Rupen, M. P.; Mioduszewski, A. J.

49

Monitoring the X-Ray Pulse Phase of the Crab Pulsar with RXTE  

Microsoft Academic Search

We have monitored the phase of the primary component in the X-ray pulse profile of the Crab pulsar with RXTE for almost three years. The absolute time of the Rossi X-ray Timing Explorer's clock is sufficiently accurate to allow this phase to be compared directly with the radio profile. Our monitoring observations of the pulsar took place weekly (during the

A. H. Rots; K. Jahoda; A. G. Lyne

1998-01-01

50

Broad Band Spectroscopy of Radioloud Agn: Simultaneous Rxte-Tanami Observations  

NASA Astrophysics Data System (ADS)

We propose RXTE observations quasi-simultaneous to our bimonthly monitoring observations of southern radio- and gamma-ray loud AGN within the TANAMI project. The aim of the observations is to measure the broad-band radio-optical-X-ray-gamma-ray spectral energy distribution of a sample of 10 bright southern AGN for which such information are not yet available.

Wilms, Joern

51

Long-Term Monitoring of PSR B0540-69 with RXTE  

NASA Technical Reports Server (NTRS)

RXTE has monitored PSR B0540-69, the young, Crab-like pulsar in the LMC, since early January 1999 and maintained a phase-connected timing solution. We report on a search for glitches in phase or frequency, changes in the braking index, and a determination of the pulsar position.

Marshall, Francis

2012-01-01

52

RXTE Observations of the Seyfert 2 Galaxy MrK 348.  

National Technical Information Service (NTIS)

We present RXTE monitoring observations of the Seyfert 2 galaxy Mrk 348 spanning a 6 month period. The time-averaged spectrum in the 3-20 keV band shows many features characteristic of a Compton-thin Seyfert 2 galaxy, namely a hard underlying power-law co...

D. A. Smith I. Georgantopoulos R. S. Warwick

2000-01-01

53

An Integral Monitoring of GRS1915+105: Simultaneous Observations with INTEGRAL, RXTE, the Ryle and Nancay Radio Telescopes  

NASA Astrophysics Data System (ADS)

Since the launch of INTEGRAL in late 2002 we have monitored the Galactic microquasar GRS 1915+105 with long exposures (~100 ks) pointings. All the observations have been conducted simultaneously with other instruments, in particular RXTE and the Ryle Telescope, and in some cases with others (Spitzer, Nancay, GMRT, Suzaku,...). We report here the results of 3 observations performed simultaneously with INTEGRAL, RXTE, the Ryle and Nancay radio telescopes. These observations show the so-called $\

Rodriguez, J.; Pooley, G.; Hannikainen, D. C.; Lehto, H. J.

54

RXTE, Chandra, and XMM Spectroscopy of the Fe-K Lines and Compton Reflection in Type 1 AGN  

NASA Technical Reports Server (NTRS)

This award pertains to an RXTE observation of the Seyfert 1 galaxy Akn 120. The purpose of the observation was to measure the Fe-K emission line and the Compton reflection continuum with RXTE, simultaneously with Chandra and XMM. Such measurements can severely constrain accretion disk models of the central engine since the Fe-K line emission and Compton reflection are intimately related in terms of the physics of X-ray reprocessing in optically-thick matter. Akn 120 was selected for this study because it is amongst the brightest AGN in its class and has a particularly strong and apparently broad Fe-K emission line. The results could then also be used to lay the ground work for even higher resolution studies with Astro-E2. Unfortunately, the Chandra observation was not performed but a contemporaneous XMM observation was performed by another group of researchers. Those data recently became public and can be compared with the RXTE data. In addition, non-contemporaneous observations with other missions do still provide additional important constraints (for example any non-varying line or continuum emission components can be established and used to reject or preserve various model scenarios). We analyzed the RXTE data and found a strong Fe-K emission line (resolved even with the poor resolution of RXTE), and a strong Compton-reflection continuum (see Fig. l(a)). We found that the results of archival ASCA data on Akn 120 had not been published in the literature so we analyzed the ASCA data too, in order to compare with the new RXTE data. Fig. l(b) shows that the ASCA data also reveal a strong, broad FeK emission line (but the data are not sensitive to the Compton-reflection continuum). We compared our spectral fitting results for the RXTE and ASCA data with the results from XMM and from previous RXTE observations.

Yaqoob, Tahir

2004-01-01

55

RXTE timing and spectroscopy of a black hole X-ray binary in outburst  

NASA Technical Reports Server (NTRS)

Under this program, RXTE observed the Galactic black hole candidate X-ray binary H1743-322. Observations were made simultaneously in the X-ray and radio bands with Chandra and the VLA, respectively. First results from this multi-wavelength study have been reported in two papers published in refereed journals, one focusing on timing results and the other focusing on spectroscopy. The timing studies revealed high frequency QPOs at approximately 180 Hz and 240 Hz, likely in a 2:3 frequency ratio as predicted by some models. The RXTE spectra were remarkable in that they showed no evidence of disk reflection or line emission, both of which are expected in black holes.

Miller, Jon; Swank, Jean (Technical Monitor)

2005-01-01

56

RXTE Timing and Spectroscopy of a Black Hole X-Ray Binary in Outburst  

NASA Astrophysics Data System (ADS)

RXTE is ideally suited to revealing the innermost environment in Galactic black holes. Our program has discovered fast (> 100 Hz) QPOs in 2:3 or 1:2:3 ratios and skewed Fe K lines in a number of BHs; both can be used to measure spin. Our studies of spectral parameters with L_X suggest that an unknown parameter may be as important as m-dot in driving state transitions. We propose to reveal improved evidence of BH spin and and to test models for simult. high frequency QPOs in BHs as rigidly as those proposed to describe kHz QPOs in NS systems. We request 1.0 Msec to intensively study a transient Galactic BH in outburst with RXTE, aided by our global campaign covering the radio, IR, optical, soft X-rays via Chandra (200 ksec, AO-5), and hard-X-rays via Integral (600~ksec, AO-2, subm.).

Miller, Jon

57

Observation of Nonthermal Emission from the Supernova Remnant IC443 with RXTE  

NASA Technical Reports Server (NTRS)

In this paper we present analysis of X-ray spectra from the supernova remnant IC443 obtained using the PCA on RXTE. The spectra in the 3 - 20 keV band are well fit by a two-component model consisting of thermal and nonthermal components. We compare these results with recent results of other X-ray missions and discuss the need for a cut-off in the nonthermal spectrum. Recent Chandra and XMM-Newton observations suggest that much of the nonthermal emission from IC443 can be attributed to a pulsar wind nebula. We present the results of our search for periodic emission in the RXTE PCA data. We then discuss the origin o f the nonthermal component and its possible association with the unidentified EGRET source.

Sturner, S. J.; Keohane, J. W.; Reimer, O.

2002-01-01

58

Swift, INTEGRAL, RXTE, and Spitzer Reveal IGR J16283-4838  

NASA Technical Reports Server (NTRS)

We present the first combined study of the recently discovered source IGR J16283-4838 with Swift, INTEGRAL, and RXTE. The source, discovered by INTEGRAL on April 7, 2005, shows a highly absorbed (variable N(sub H) = 0.4-1.7 x 10(exp 23) /sq cm) and flat (Gamma approx. 1) spectrum in the Swift/XRT and RXTE/PCA data. No optical counterpart is detectable (V > 20 mag), but a possible infrared counterpart within the Swift/XRT error radius is detected in the 2MASS and Spitzer/GLIMPSE survey. The observations suggest that IGR J16283-4838 is a high mass X-ray binary containing a neutron star embedded in Compton thick material. This makes IGR J16283-4838 a member of the class of highly absorbed HMXBs, discovered by INTEGRAL.

Beckmann, V.; Gehrels, N.; Markwardt, C.; Barthelmy S.; Soldi, S.; Paizis, A.; Mowlavi, N.; Kennca, J. A.; Burrows, D. N.; Chester, M.

2005-01-01

59

1996\\/1997 low luminosity state and state transitions of GRS1915+105: RXTE observations  

Microsoft Academic Search

The results of X-ray observations of Galactic superluminal jet source GRS 1915+105 during its low luminosity state and state transitions in October, 1996 - April, 1997 with PCA and HEXTE instruments aboard Rossi X-ray Timing Explorer (RXTE) are reported. Except some peculiarities, the major spectral and temporal properties of the source during this period were similar to that of the

S. Trudolyubov; E. Churazov; M. Gilfanov

1998-01-01

60

Joint Rxte-Axaf Observations of the Galactic Superluminal Source GRS1915+105  

Microsoft Academic Search

Previous ASCA observations of the Galactic superluminal GRS1915+105 have revealed prominent absorption lines from highly ionized iron, possibly due to a photoionized accretion disk wind. We have an accepted program to perform high resolution spectroscopy of this system with the AXAF HETG-ACIS in order to study this wind in detail. Here we propose for simultaneous RXTE observations which will define

Christopher Reynolds

1999-01-01

61

Limits on Short-Term ( ~1000 s) Afterglows from RXTE's All Sky Monitor via Bayes  

NASA Astrophysics Data System (ADS)

Wide field of view instruments like RXTE's All-Sky Monitor (RXTE/ASM) have the possibility of tracking fading X-ray emission and any possible resurgences from the start of a gamma-ray burst until ~ thousands of seconds after. Such emssion had been detected serendipitously previously in X-rays (Connors and McConnell 1995 Rome ICRC, 2, 57; Connors and Hueter 1998 ApJ 1998ApJ 501, 307 and references therein); and been tracked at higher energies (Matz et al 1995, 1996, Huntsville Conference Proceedings). Recently, the advent of SWIFT has rekindled theoretical interest in this time frame: it may be possible to descry clues to the slowing and spreading of this high energy, relativistically beamed material; and its progress through its local interstelar matter. However the signal--to--noise ratio could be quite low. Therefore we created a Bayesian tool to map out the likelihood of the intensity of a source of interest, for every 90 s snapshot that it is in the field of view (marginalizing over all ``uninteresting'' parameters such as other sources and the background rates). This is guarenteed to extract all the inforamtion in the data about the flux, but it can be very CPU intensive. We are now applying this to all bursts RXTE/ASM, and will make these Bayes light--curves available for further analysis. This is funded by NASA Grant NAG5-8476.

Connors, A.; Smith, D. A.

2000-12-01

62

A Year of Hands-on Science: Exciting Theme Units with More Than 100 Activities, Projects, and Experiments To Make Science Come Alive.  

ERIC Educational Resources Information Center

This book contains 18 themed teaching units with 2 themes per chapter, organized seasonally around the traditional school year. Each theme includes natural connections and hands-on science activities that correspond to what children are already observing in their world. Each chapter begins with highlights of the month and a reproducible "Science

Kepler, Lynne; Novelli, Joan, Ed.

63

Map, Excite, Jump, and Measure: An Outreach Activity That Utilizes Seismology to Engage Students in Technology, Science, Engineering, and Mathematics  

NASA Astrophysics Data System (ADS)

We designed and will present a lesson plan to teach students STEM concepts through seismology. The plan addresses new generation science standards in the Framework for K-12 Science Education as well AAAS Benchmarks for Science Literacy. The plan can be executed at a facility with a seismometer in a research facility or university, on a field trip, but it can also be used in a school setting with a school seismometer. Within the lesson plan, the students first use technology to obtain earthquake location data and map them. Next, the students learn about the science of earthquakes, which is followed by an engineering activity in which the students design a hypothetical seismometer and interact with the actual seismometer and live data display. Lastly the students use mathematics to locate an earthquake through trilateration. The lesson plan has been fine-tuned through implementation with over 150 students from grades 3-12 from the Chicago area.

van der Lee, S.; Tekverk, K.; Rooney, K.; Boxerman, J.

2013-12-01

64

Discovery of kilohertz QPOs in RXTE observations of SAX J1748.9-2021.  

NASA Astrophysics Data System (ADS)

We report on RXTE observations of the ongoing outburst of the accreting millisecond X-ray pulsar SAX J1748.9-2021 (Altamirano et al. 2008, 674, 45A, see ATEL #2360 and #2407). Since the first detection of intermittent pulsations on January 27th, 2010, observations have been carried out on a daily basis. The source remained between 120 and 160 mCrab (2-16 keV - see ATEL #2407) until February 3rd, when the intensity started to decrease.

Altamirano, D.; Patruno, A.; Watts, A.; Armas Padilla, M.; Cavecchi, Y.; Degenaar, N.; Kalamkar, M.; Kaur, R.; Soleri, P.; Yang, Y. J.; van der Klis, M.; Wijnands, R.; Casella, P.; Linares, M.; Rea, N.

2010-02-01

65

RXTE Monitoring of Cyg X-1 in its current transitional state  

NASA Astrophysics Data System (ADS)

RXTE has performed pointed observations of Cyg X-1 on 2010-06-19/20, 2010-07-04, and 2010-07-19/20. Following the AGILE detections (ATel #2512, #2715) and subsequent observations indicating a softening of the source (Atel #2711, #2714, #2721, #2724, #2734) ending a years long hard state (Nowak et al., POS MQW7, 2008), we performed spectral and timing analysis of these observations. The X-ray spectrum can be well described by the sum of an absorbed broken power law and a black body.

Grinberg, V.; Boeck, M.; Pottschmidt, K.; Nowak, M. A.; Uttley, P.; Tomsick, J. A.; Bodaghee, A.; Markoff, S.; Pooley, G.; Kreykenbohm, I.; Wilms, J.

2010-07-01

66

Multiwavelength observations of LS I +61\\circ 303 with VERITAS, Swift and RXTE.  

SciTech Connect

We present results from a long-term monitoring campaign on the TeV binary LSI +61{sup o} 303 with VERITAS at energies above 500 GeV, and in the 2-10 keV hard X-ray bands with RXTE and Swift, sampling nine 26.5 day orbital cycles between 2006 September and 2008 February. The binary was observed by VERITAS to be variable, with all integrated observations resulting in a detection at the 8.8{sigma} (2006/2007) and 7.3{sigma} (2007/2008) significance level for emission above 500 GeV. The source was detected during active periods with flux values ranging from 5% to 20% of the Crab Nebula, varying over the course of a single orbital cycle. Additionally, the observations conducted in the 2007-2008 observing season show marginal evidence (at the 3.6{sigma} significance level) for TeV emission outside the apastron passage of the compact object around the Be star. Contemporaneous hard X-ray observations with RXTE and Swift show large variability with flux values typically varying between 0.5 and 3.0 x 10{sup -11} erg cm{sup -2} s{sup -1} over a single orbital cycle. The contemporaneous X-ray and TeV data are examined and it is shown that the TeV sampling is not dense enough to detect a correlation between the two bands.

Byrum, K.; Smith, A. W.; Wagner, R. G; Acciari, V. A; Aliu, E.; Arlen, T.; Bautista, M.; Beilicke, M. (High Energy Physics); (Galway-Mayo Inst. of Tech.); (Univ. of Delaware); (Univ. of California); (McGill Univ.); (Washington Univ.)

2009-04-01

67

Studies of Accreting Neutron Stars with RXTE Cycle 4 Observations: II: Too Observations of Transient LMXBs  

NASA Technical Reports Server (NTRS)

NASA Grant NAG 5-9045 provided funds for the research project 'TOO Observations of Transient LMxBs' approved under the Rossi X-ray Timing Explorer (RXTE) Guest Observer Program Cycle 4 and funded under the 1999 NASA Astrophysics Data Program. The principal investigator of the observing time proposal was Dr. M. Mendez (U. of Amsterdam). The grant was funded for one year beginning 3/1/2000. The original proposal was submitted by Prof. Jan van Paradijs, who passed away in 1999 before the funds were distributed. Prof. William S. Pauesas administered the grant during the period of performance. In spite of a wealth of observational data on the kHz QPO in low-mass X-ray binaries (LMXBs), the interpretation of this phenomenon is currently uncertain because the pairs of kHz QPO peaks and the oscillations seen in some Type I X-ray bursts are almost, but not quite, connected by a simple beat frequency relation. The proposal was intended to contribute to a solution to this confusion by making RXTE target-of-opportunity observations of two transient LMXBs, Aql X-1 and 4U 1608-52, if the sources became sufficiently bright.

Paciesas, William S.

2002-01-01

68

Food Science.  

ERIC Educational Resources Information Center

Presents food science experiments designed for high school science classes that aim at getting students excited about science and providing them with real-life applications. Enables students to see the application of chemistry, microbiology, engineering, and other basic and applied sciences to the production, processing, preservation, evaluation,…

Barkman, Susan J.

1996-01-01

69

How to Use a Bed of Nails to Facilitate Excitement during a Science Road Show Presentation at Local Schools  

NASA Astrophysics Data System (ADS)

The authors will demonstrate how to use a bed of nails to pump up the students at local K-12 schools. The use during Science Road Show presentations will be addressed along with suggestions on how to build the drama and introduce humor and learning.

Pena, Fabian; Kridler, Shawn; Berger, Pete

2008-03-01

70

An Integral Monitoring of GRS1915+105: Simultaneous Observations with INTEGRAL, RXTE, the Ryle and Nancay Radio Telescopes  

Microsoft Academic Search

Since the launch of INTEGRAL in late 2002 we have monitored the Galactic microquasar GRS 1915+105 with long exposures (~100 ks) pointings. All the observations have been conducted simultaneously with other instruments, in particular RXTE and the Ryle Telescope, and in some cases with others (Spitzer, Nancay, GMRT, Suzaku,...). We report here the results of 3 observations performed simultaneously with

J. Rodriguez; G. Pooley; D. C. Hannikainen; H. J. Lehto

2007-01-01

71

Science  

NSDL National Science Digital Library

Science Magazine online. Access abstracts and full text articles updated weekly. Browse through the current issue or archived articles. Obtain information on magazine subscriptions and student, educator, and scientist awards. A wealth of science information is at your fingertips in all disciplines, particularly medicine. Links to other AAAS resources including extensive career information and the latest in HIV/AIDS and aging research.

72

Science.  

ERIC Educational Resources Information Center

This document contains the following papers on science instruction and technology: "A 3-D Journey in Space: A New Visual Cognitive Adventure" (Yoav Yair, Rachel Mintz, and Shai Litvak); "Using Collaborative Inquiry and Interactive Technologies in an Environmental Science Project for Middle School Teachers: A Description and Analysis" (Patricia…

Roach, Linda E., Ed.

73

X-ray transients monitored by the all-sky monitor on RXTE: A tabulation  

NASA Astrophysics Data System (ADS)

We present a tabulation of 46 transient x-ray sources monitored with the All-Sky Monitor (ASM) on the Rossi X-ray Timing Explorer (RXTE). They fall into four broad categories: short (~1 d), intermediate, and long (>500 d) duration of outbursts, and long period binary systems that flare up at periastron (e.g., Be systems). The mixture of outburst/quiescent cycles and low-level persistent emission in a few systems could indicate conditions are near the limit for stable mass flow in the accretion disk. The two short-time-scale systems, CI Cam and V4641 Sgr, are within 1 kpc of the sun, and hence many more such systems may await discovery. .

Bradt, Hale; Levine, Alan; Remillard, Ronald; Smith, Donald A.

2001-12-01

74

RXTE Discovery of the Spin Period of Swift J1834.9-0846  

NASA Astrophysics Data System (ADS)

RXTE/PCA observed the new source, Swift J1834.9-0846 (D'Elia et al. GCN Circ. 12253, Guiriec et al. 12255) on 2011 August 9-10, for a net exposure time of 9.7 ks. We performed a timing analysis using the barycentered photon arrival times in the 2-10 keV band and detected a coherent pulsation at 0.402853(2) Hz which corresponds to a spin period of 2.482295 s. Note that an earlier PCA observation on 2011 August 9 of the same field with a 3.4 ks exposure did not reveal the pulsed signal clearly but it does confirm the signal at a consistent frequency.

Gogus, Ersin; Kouveliotou, Chryssa

2011-08-01

75

RXTE Observations of A1744-361: Correlated Spectral and Timing Behavior  

NASA Technical Reports Server (NTRS)

We analyze Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) data of the transient low mass X-ray binary (LMXB) system A1744-361. We explore the X-ray intensity and spectral evolution of the source, perform timing analysis, and find that A1744-361 is a weak LMXB, that shows atoll behavior at high intensity states. The color-color diagram indicates that this LMXB was observed in a low intensity spectrally hard (low-hard) state and in a high intensity banana state. The low-hard state shows a horizontal pattern in the color-color diagram, and the previously reported dipper QPO appears only during this state. We also perform energy spectral analyses, and report the first detection of broad iron emission line and iron absorption edge from A1744-361.

Bhattacharyya, Sudip; Strohmayer, Tod E.; Swank, Jean H.; Markwardt, Craig B.

2007-01-01

76

IGR J19140+0951 as seen by INTEGRAL and RXTE.  

NASA Astrophysics Data System (ADS)

IGR J19140+0951 was discovered during the first observation campaign of the famous micro quasar GRS1915+105 by the IBIS/ISGRI detector onboard INTEGRAL. The source which is ~1 degree from from GRS1915+105, shows strong X-ray luminosity and spectral variations on timescales from seconds to hours. We report here the results obtained from our AO1 INTEGRAL campaign and observations of the source during Galactic Plane Scans and Galactic Centre Deep Exposure as well as RXTE observations. We study the high energy spectral and timing properties of the source, and propose it to be a Galactic X-ray binary. We also discuss the type of the compact object based on the spectral parameters of the source.

Rodriguez, J.; Cabanac, C.; Hannikainen, D. C.

2004-12-01

77

Neutron Stars and Black Holes Seen with the Rossi X-Ray Timing Explorer (RXTE)  

NASA Technical Reports Server (NTRS)

Astrophysical X-rays bring information about location, energy, time, and polarization. X-rays from compact objects were seen in the first explorations to vary in time. Eclipses and pulsations have simple explanations that identified the importance of X-ray binaries and magnetic neutron stars in the first decade of X-ray astronomy. The dynamics of accretion onto stellar and supermassive black holes and onto neutron stars with relatively low magnetic fields shows up as more complex variations, quasi-periodic oscillations, noise with characteristic frequency spectra, broad-band changes in the energy spectra. To study these variations, RXTE instruments needed to have large area and operational flexibility to find transient activity and observe when it was present. Proportional counters and Phoswich scintillators provided it in a modest mission that has made textbook level contributions to understanding of compact objects. The first seen, and the brightest known, X-ray binary, Sco X-1 is one of a class of neutron stars with low mass companions. Before RXTE, none of these had been seen to show pulsations, though they were hypothesized to be the precursors of radio pulsars with millisecond periods and low magnetic fields. RXTE's large area led to identifying coherent millisecond pulsars in a subset which are relatively faint transients. It also led to identifying short episodes of pulsation during thermonuclear bursts, in sources where a steady signal is not seen. The X-ray stage verifies the evolution that produces millisecond radio pulsars.Masses and radii of neutron stars are being determined by various techniques, constraining the equation of state of matter at nuclear densities. Accretion should lead to a range of neutron star masses. An early stage of superstrong magnetic field neutron stars is now known to produce X-ray and gamma-ray bursts in crust quakes and magnetic field reconnection releases of energy. Soft Gamma Repeaters, Anomolous X-ray Pulsars, and high magnetic field rotation-powered pulsars are all now called magnetars, because they have pulse periods indicating they are slowing down as they would with magnetic dipole radiation for a surface field above 5x1013 gauss. The accretion disk has been connected to the launching of radio jets from black holes, and even from neutron stars. Estimates of the angular momenta of black holes are being made from different approaches, modelling a high frequency oscillation that may be related to how close the inner part of the accretion disk is to the black hole, modelling the continua spectra of the X-ray emission, and modeling the emission of red-shifted iron that may be emitted from the accretion disk. These investigations require early discovery of the black hole transient with the All Sky Monitor on RXTE or other monitoring information, frequent extended observations, and coordinated observations with missions that give higher energy resolution, or radio and infrared information.

Swank, Jean

2008-01-01

78

Peculiar Outburst of A 0535+26 Observed with INTEGRAL, RXTE and Suzaku  

NASA Technical Reports Server (NTRS)

A normal outburst of the Be/X-ray binary system A0535+26 has taken place in August 2009. It is the fourth in a series of normal outbursts that have occurred around the periastron passage of the source. but is unusual by starting at an earlier orbital phase and by presenting a peculiar double-peaked light curve. A first "flare" (lasting about 9 days from M.ID 55043 on) reached a flux of 440 mCrab. The flux then decreased to less than 220 mCrab. and increased again reaching 440 mCrab around the periastron at MJD 55057. Target of Opportunity observations have been performed with INTEGRAL. RXTE and Suzaku. First results of these observations are presented. with special emphasis on the cyclotron lines present in the X-ray spectrum of the source. as well as in the pulse period and energy dependent pulse profiles of the source

Caballero, I.; Pottschmidt, K.; Barragan, L.; Ferrigno, C.; Kretschmar, P.; Suchy, S.; Wilms, J.; Santangelo, A.; Kreykenbohm, I.; Rothschild, R.; Klochkov, D.; Staubert, R.; Finger, M. H.; Camero-Arranz, A.; Makishima, K.; Enoto, T.

2009-01-01

79

RXTE PCA Upper Limit on X-Ray Flux from V1280 Sco  

NASA Astrophysics Data System (ADS)

Two perpendicular scans over the position of V1280 Sco were carried out with the RXTE PCA on Feb 21, 2007 between 18:54 UT and 19:27 UT. The data from detector 2 (which has the particle protection of a propane layer) give a 3 sigma upper limit contribution of V1280 Sco of 0.15 mCrab or 3.6x10^-12 ergs cm^-2 s^-1, 2-10 keV. Detectors 0 and 1 were also used during the observation. Preliminary analysis of detectors 0, 1, and 2 together gives a best fit of 0.12 mCrab, but only at a level of 2.4 sigma due to higher background variations.

Swank, J. H.

2007-02-01

80

The properties of Hercules X-1 measured with 14 years of RXTE/PCA observations  

NASA Astrophysics Data System (ADS)

Hercules X-1 was observed by the Rossi X-Ray Timing Explorer/Proportional Counter Array (RXTE/PCA) over a period of about 14 years. The observations include times that Her X-1 is in the main high, short high, and low states, and also the anomalous low state (ALS). We present an overview of the light curves of Her X-1 in the various states and compare their properties, noting especially the similarities of the normal low states and the anomalous low states. We examine the times of X-ray eclipses in more detail and present a new analysis including time-resolved spectroscopy of ingress, egress and mid-eclipse periods. The variation of spectral parameters from eclipse to eclipse are compared. The results discussed in terms of interpretation for the time-varying system geometry, including precession of a warped accretion disk.

Leahy, Denis; Abdullah, Mohammed

2012-07-01

81

A Simple Method to Improve the Quality of RXTE PCA Spectra  

NASA Astrophysics Data System (ADS)

We fitted at once all of the several hundred RXTE PCA spectra of the Crab to a simple power-law model; the total number of counts in the composite spectrum is >10^9. We then used the spectrum of fit residuals (data/model) to correct large samples of spectra of G 339-4, H1743-322, and XTE J1550-564. The correction improved the quality of all the fits, and the improvement was dramatic for spectra with >10^7 counts. The Crab residual spectrum is somewhat different for each of the five PCA detectors, but it was relatively stable during the course of the 16-year mission. We provide public software that automates the process of applying the correction to PCA data and recommend that the correction be applied to all spectra with >10^6 counts.

Garcia, Javier; McClintock, Jeffrey E.; Steiner, James F.; Remillard, Ronald A.; Grinberg, Victoria

2014-06-01

82

A DOUBLE-PEAKED OUTBURST OF A 0535+26 OBSERVED WITH INTEGRAL, RXTE, AND SUZAKU  

SciTech Connect

The Be/X-ray binary A 0535+26 showed a normal (type I) outburst in 2009 August. It is the fourth in a series of normal outbursts associated with the periastron, but is unusual because it presented a double-peaked light curve. The two peaks reached a flux of {approx}450 mCrab in the 15-50 keV range. We present results of the timing and spectral analysis of INTEGRAL, RXTE, and Suzaku observations of the outburst. The energy-dependent pulse profiles and their evolution during the outburst are studied. No significant differences with respect to other normal outbursts are observed. The centroid energy of the fundamental cyclotron line shows no significant variation during the outburst. A spectral hardening with increasing luminosity is observed. We conclude that the source is accreting in the sub-critical regime. We discuss possible explanations for the double-peaked outburst.

Caballero, I. [Laboratoire AIM, CEA/IRFU, CNRS/INSU, Universite Paris Diderot, CEA DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); Pottschmidt, K.; Marcu, D. M. [Center for Space Science and Technology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Barragan, L.; Wilms, J.; Kreykenbohm, I. [Dr. Karl Remeis-Sternwarte and ECAP, FAU Erlangen-Nuremberg, Sternwartstr. 7, D-96049 Bamberg (Germany); Ferrigno, C. [ISDC Data Centre for Astrophysics, University of Geneva, Chemin d'Ecogia 16, CH-1290 Versoix (Switzerland); Klochkov, D.; Suchy, S.; Santangelo, A.; Staubert, R. [Institut fuer Astronomie und Astrophysik, Sand 1, D-72076 Tuebingen (Germany); Zurita Heras, J. A. [Francois Arago Centre, APC (UMR 7164 Universite Paris Diderot, CNRS/IN2P3, CEA/DSM, Observatoire de Paris), 13 rue Watt, F-75205 Paris Cedex 13 (France); Kretschmar, P. [European Space Astronomy Centre (ESA/ESAC), Science Operations Department, Villanueva de la Canada, E-28080 Madrid (Spain); Fuerst, F. [Space Radiation Lab, California Institute of Technology, MC 290-17 Cahill, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Rothschild, R. [Center for Astrophysics and Space Science, UCSD, La Jolla, CA 92093 (United States); Finger, M. H. [National Space Science and Technology Center, 320 Sparkman Drive NW, Huntsville, AL 35805 (United States); Camero-Arranz, A. [Institut de Ciencies de l'Espai (IEEC-CSIC), Campus UAB, Fac. de Ciencies, Torre C5, parell, 2a planta, E-08193 Barcelona (Spain); Makishima, K. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Enoto, T. [Cosmic Radiation Laboratory, RIKEN, 2-1, Hirosawa, Wako City, Saitama 351-0198 (Japan); Iwakiri, W., E-mail: isabel.caballero@cea.fr [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura, Saitama 338-8570 (Japan); and others

2013-02-20

83

Observations of Type I X-ray Bursts from GS 1826-238 with RXTE  

NASA Technical Reports Server (NTRS)

The analysis of the XMM data is complete. Additional RXTE data were used to determine the underlying continuum of the XMM spectra. A few spectral lines (with low significance) are present in the XMM-Newton data of the Type I bursts of GS 1826-238. In spite of numerous efforts, we cannot identify these lines; perhaps they are not real. The bottom line is that we are unable to determine the gravitational redshift from the surface of the neutron star in GS 1826-238. A gravitational redshift was earlier reported using spectra of Type I bursts observed with XMM-Newton from EX0 0748-676 (Cottam et al., Nature). However, renewed observations by Cottam et al. of EX0 0748-676 with XMM-Newton do not confirm their earlier results. Our adopted Co-I Mario Mendez is presently working on a paper which finalizes our conclusions for GS 1826-238.

Lewin, Walter; Paerels, F.; Miller, J.; Pooley, D.; Wijnands, R.; Kuulkers, E.; VanderKlis, M.

2005-01-01

84

Studies of Accreting Neutron Stars with RXTE Cycle 4 Observations: III: TOO Observations of Atoll Sources  

NASA Technical Reports Server (NTRS)

NASA Grant NAG 5-9244 provided funds for the research projects 'ASM-Triggered TOO Observations of Kilohertz Oscillations in Five Atoll Sources' and 'Further Measurements of the Kilohertz Oscillations in 4U 1705-44' approved under the Rossi X-ray Timing Explorer (RXTE) Guest Observer Program Cycle 4 and funded under the 1999 NASA Astrophysics Data Program. The principal investigator of the observing time proposals was Dr. E. C. Ford (U. of Amsterdam). The grant was funded for one year beginning 3/15/2000. The original ADP proposal was submitted by Prof. Jan van Paradijs, who passed away in 1999 before the funds were distributed. Prof. Wilham S. Padesas administered the grant during the period of performance. In spite of a wealth of observational data on the kHz QPO in low-mass X-ray binaries (LMXBs), the interpretation of this phenomenon is currently uncertain because the pairs of kHz QPO peaks and the oscillations seen in some Type I X-ray bursts are almost, but not quite, connected by a simple beat frequency relation. Further systematic studies of systems with known QPOs are required in order to better understand the phenomenon. The proposals were intended to contribute to a solution to this confusion by observing the sources as they vary over a wide range of X-ray flux. RXTE target-of-opportunity observations of six transient atoll sources, 4U 0614+09, KS 1732-260, Ser X-1, 4U 1702-42, 4U 1820-30 and 4U 1705-44 were to be performed at various flux levels based on ASM measurements.

Paciesas, William S.

2002-01-01

85

Eclipse Observations of EXO 0748-676 and X1658-298 with RXTE  

NASA Astrophysics Data System (ADS)

The orbital period derivative is a critical diagnostic of LMXB evolution. We now have 182 RXTE mid-eclipse time measurements in hand for the LMXB EXO0748-676. When combined with earlier measurements from other satellites we have a total of over 230 mid-eclipse timings for this source. For the transient LMXB X1658-298 we have 50 measured mid-eclipse times. For EXO0748-676 we find that a piecewise linear constant period model for the orbit period evolution between the discovery in 1985 and the present shows remarkable behavior. The EXO0748-676 orbital period appears to increase near MJD 48000 by ˜ 8 msec but then appears to decrease again near MJD 51700 by ˜ 6.7 msec! In the case of X1658-298 our observations show that the 7.1-hr orbital period of this system is decreasing with a time scale of ? orb ˜ 4-10 x 107 yr. The orbit period behavior in EXO0748-676 is difficult to understand in the context of current models of LMXB evolution. In the case of X1658-298 the period derivative appears close to values predicted by some LMXB evolutionary models. However, the magnitude of the orbital period derivative for this source is still difficult to understand because little or no mass transfer is thought to have occurred while the system was in quiescence during the interval 1978-1999. We apply maximum likelihood statistical methods to these data to quantify the intrinsic phase variability and the orbital period variability for both systems over the past 22 years. We report the latest results of our program of eclipse observations of EXO0748-676 and X1658-298 with RXTE. This research is supported by the Office of Naval Research and the NASA Astrophysical Data Program.

Wolff, M. T.; Ray, P. S.; Wood, K. S.; Smale, A. P.

2003-03-01

86

Understanding Science  

NSDL National Science Digital Library

The mission of Understanding Science is to provide a fun, accessible, and free resource that accurately communicates what science is and how it really works. The process of science is exciting, but standard explanations often miss its dynamic nature. Science affects us all everyday, but people often feel cut off from science. Science is an intensely human endeavor, but many portrayals gloss over the passion, curiosity, and even rivalries and pitfalls that characterize all human ventures. Understanding Science gives users an inside look at the general principles, methods, and motivations that underlie all of science.

2009-01-01

87

The Crab Pulsar Observed by RXTE: Monitoring the X-Ray to Radio Delay for 16 Years  

NASA Technical Reports Server (NTRS)

In 2004 we published the results of monitoring the Crab Pulsar by RXTE. At that time we determined that the primary pulse of the pulsar at X-ray energies precedes its radio counterpart by about 0.01 period in phase or approximately 330 micro seconds. However, we could not establish unambiguously whether the delay is in phase or due to a difference in pathlength. At this time we have twice the time baseline we had in 2004 and we present the same analysis, but now over a period of 16 years, which will represent almost the full mission and the best that will be available from RXTE. The full dataset shows that the phase delay has been decreasing faster than the pulse frequency over the 16 year baseline and that there are variations in the delay on a variety of timescales.

Rots, Arnold; Jahoda, Keith

2012-01-01

88

RXTE, Integral and Radio Observations of the Black Hole X-Ray Transient 4u 1630-47  

NASA Astrophysics Data System (ADS)

The recurrent black hole transient 4U 1630-47 is currently undergoing its longest and brightest outburst of the RXTE era. We have observed this source with INTEGRAL during this outburst, and we have proposed for two more INTEGRAL observations in cycle 2. The broadband spectral and timing properties will allow us to place constraints on accretion geometries and emission mechanisms, and we plan to search for high energy emission lines with INTEGRAL. Radio observations will be made to determine if there is a relationship between the high energy emission and radio jets. RXTE observations are crucial for triggering one of the INTEGRAL observations and for providing timing information and constraining the soft X-ray portion of the spectrum during both of the INTEGRAL observations.

Tomsick, John

89

RXTE Observations of 0.1-300 Hz QPOs in the Microquasar GRO J1655-40  

Microsoft Academic Search

We have investigated 52 RXTE pointed observations of GRO J1655-40 spanning the X-ray outburst that commenced on 1996 April 25 and lasted for 16 months. Our X-ray timing analyses reveal four types of QPOs: three with relatively stable central frequencies at 300 Hz, 9 Hz, and 0.1 Hz, and a fourth that varied over the range 14-28 Hz. The 300

R. A. Remillard; E. H. Morgan; J. E. McClintock; C. D. Bailyn; J. A. Orosz

1998-01-01

90

An integral monitoring of GRS1915+105: simultaneous observations with INTEGRAL, RXTE, the Ryle and Nancay radio telescopes  

Microsoft Academic Search

Since the launch of INTEGRAL in late 2002 we have monitored the Galactic\\u000amicroquasar GRS 1915+105 with long exposures (~100 ks) pointings. All the\\u000aobservations have been conducted simultaneously with other instruments, in\\u000aparticular RXTE and the Ryle Telescope, and in some cases with others (Spitzer,\\u000aNancay, GMRT, Suzaku,...). We report here the results of 3 observations\\u000aperformed simultaneously with

J. Rodriguez; G. Pooley; D. C. Hannikainen; H. J. Lehto

2006-01-01

91

Combined long and short time-scale X-ray variability of NGC 4051 with RXTE and XMM-Newton  

Microsoft Academic Search

We present a comprehensive examination of the X-ray variability of the narrow-line Seyfert 1 (NLS1) galaxy NGC 4051, one of the most variable active galactic nuclei (AGN) in the sky. We combine over 6.5 years of frequent monitoring observations by RXTE with a >100-ks continuous observation by XMM-Newton and so present an overall 2-10 keV power spectral density (PSD) covering

I. M. McHardy; I. E. Papadakis; P. Uttley; M. J. Page; K. O. Mason

2004-01-01

92

IGR J17091-3624 shows a unique quasi-'rho' class variability during recent RXTE\\/PCA observations  

Microsoft Academic Search

Recent RXTE\\/PCA observations of the black hole low mass X-ray binary IGR J17091-3624 showed a unique quasi-'rho' class variability. This variability consisted of oscillations with very large amplitude and oscillations with small amplitude. Both oscillations occurred alternately for a certain interval of time. Interestingly, both oscillations have same timescale and seen first time in this source.

Mayukh Pahari; J. S. Yadav; Sudip Bhattacharyya

2011-01-01

93

RXTE\\/PCA detection of QPO near 0.22 Hz in Aql X-1 during ongoing outburst  

Microsoft Academic Search

We have analyzed eight RXTE\\/PCA archived observations (2-15 September 2010) of the current outburst of the neutron star Aql X-1 occurred during September 2010 (ATEL #2850, #2871). We have detected QPO near 0.22 Hz in the power density spectrum (with the frequency bin of 1\\/256 Hz) in one observation on 2nd September 2010 with a significance of 5.1sigma. The other

Mayukh Pahari; Sabyasachi Pal; Arunava Mukherjee

2010-01-01

94

RXTE Monitoring of the Supermassive Star eta Car Colliding Wind Emission in a Pre-Hypernova Candidate Binary?  

Microsoft Academic Search

Our detailed RXTE monitoring of the supermassive ``pre-hypernova-candidate'' star eta Carina shows that the X-ray ``low state'' recurs with the optical period of 5.52-years. We interpret this fundamental X-ray variability in terms of a binary model in which the observed variations can mainly be attributed to collisions of 2 extraordinarily powerful stellar winds. However, there are interesting discrepancies between the

Michael Corcoran; Kazunori Ishibashi; Kris Davidson; Jean Swank; Rob Petre; Steve Drake; Augusto Damineli

1999-01-01

95

RXTE/PCA observations of Hercules X-1: New features of the orbital and 35-day folded light curves  

NASA Astrophysics Data System (ADS)

Hercules X-1 is a well-known and much studied X-ray binary. It is a 1.7 day eclipsing system and has a 35-day cycle consisting of consecutive high, low, short-high and low states. The cause of the cycle is understood to be changing obscuration of the line-of-sight to the neutron star by a warped accretion disk, which precesses with a 35 day period. All of the X-ray observations of Hercules X-1 taken with the Proportional Counter Array (PCA) instrument of the Rossi X-ray Timing Explorer (RXTE) satellite are analyzed. 35-day phase is determined using a study of RXTE All Sky Monitor data and verified with the PCA data. New orbital and 35-day folded light curves are presented. Absorption dips are identified and studied as a function of orbital and 35-day phase. The extensive RXTE/PCA data give a considerably better and different picture of the dip phenomena than previously possible.

Leahy, Denis; Igna, Ciprian

2012-03-01

96

Science for All.  

ERIC Educational Resources Information Center

Science education should be effective as "Science for All" but the science curriculums introduced in the 1960s and 1970s were inadequate and only served a science "elite" while teaching the majority of students that science was not for them. Science must be reexamined and curriculum developers should emphasize exciting examples and everyday…

Fensham, Peter J.

1987-01-01

97

LMC X-1 and LMC X-3 as Seen by RXTE  

NASA Technical Reports Server (NTRS)

LMC X-1 and LMC X-3 are the only two black holes that are consistently seen in the soft X-ray state. We present the results from the spectral and temporal analysis of a long (150 ksec) observation of these two objects. The spectra can be well described by a disk black body plus a high energy power-law, which extends to at least 50keV. Starting in December 1996 we have also monitored these objects with RXTE in about three to four week intervals. We present the evolution of the spectral parameters of the sources from the first twenty pointings. LMC X-1 has a very stable spectrum and does not exhibit any large scale variability. On the other hand, the appearance of LMC X-3 changes considerably over its 200d long cycle. This variability can either be explained by periodic changes in the mass transfer rate or by a precessing accretion disk analogous to Her X-1.

Wilms, J.; Nowak, M. A.; Dove, J. B.; Pottschmidt, K.; Heindl, W. A.; Begelman, M. C.; Staubert, R.

1998-01-01

98

Analysis of systematic errors of the ASM/RXTE monitor and GT-48 ?-ray telescope  

NASA Astrophysics Data System (ADS)

The observational data concerning variations of light curves of supernovae remnants—the Crab Nebula, Cassiopeia A, Tycho Brahe, and pulsar Vela—over 14 days scale that may be attributed to systematic errors of the ASM/RXTE monitor are presented. The experimental systematic errors of the GT-48 ?-ray telescope in the mono mode of operation were also determined. For this the observational data of TeV J2032 + 4130 (Cyg ?-2, according to the Crimean version) were used and the stationary nature of its ?-ray emission was confirmed by long-term observations performed with HEGRA and MAGIC. The results of research allow us to draw the following conclusions: (1) light curves of supernovae remnants averaged for long observing periods have false statistically significant flux variations, (2) the level of systematic errors is proportional to the registered flux and decreases with increasing temporal scale of averaging, (3) the light curves of sources may be modulated by the year period, and (4) the systematic errors of the GT-48 ?-ray telescope, in the amount caused by observations in the mono mode and data processing with the stereo-algorithm come to 0.12 min-1.

Fidelis, V. V.

2011-06-01

99

Cryogenic exciter  

DOEpatents

The disclosed technology is a cryogenic static exciter. The cryogenic static exciter is connected to a synchronous electric machine that has a field winding. The synchronous electric machine is cooled via a refrigerator or cryogen like liquid nitrogen. The static exciter is in communication with the field winding and is operating at ambient temperature. The static exciter receives cooling from a refrigerator or cryogen source, which may also service the synchronous machine, to selected areas of the static exciter and the cooling selectively reduces the operating temperature of the selected areas of the static exciter.

Bray, James William (Niskayuna, NY); Garces, Luis Jose (Niskayuna, NY)

2012-03-13

100

RXTE Observations of the Seyfert 2 Galaxy MrK 348  

NASA Technical Reports Server (NTRS)

We present RXTE monitoring observations of the Seyfert 2 galaxy Mrk 348 spanning a 6 month period. The time-averaged spectrum in the 3-20 keV band shows many features characteristic of a Compton-thin Seyfert 2 galaxy, namely a hard underlying power-law continuum (Gamma approximately equal 1.8) with heavy soft X-ray absorption (N(sub H) approximately 10(exp 23)/sq cm) plus measurable iron K.alpha emission (equivalent width approximately 100 eV) and, at high energy, evidence for a reflection component (R approximately < 1). During the first half of the monitoring period the X-ray continuum flux from Mrk 348 remained relatively steady. However this was followed by a significant brightening of the source (by roughly a factor of 4) with the fastest change corresponding to a doubling of its X-ray flux on a timescale of about 20 days. The flux increase was accompanied by a marked softening of X-ray spectrum most likely attributable to a factor approximately 3 decline in the intrinsic line-of-sight column density. In contrast the iron K.alpha line and the reflection components showed no evidence of variability. These observations suggest a scenario in which the central X-ray source is surrounded by a patchy distribution of absorbing material located within about a light-week of the nucleus of Mrk 348. The random movement of individual clouds within the absorbing screen, across our line of sight, produces substantial temporal variations in the measured column density on timescales of weeks to months and gives rise to the observed X-ray spectral variability. However, as viewed from the nucleus the global coverage and typical thickness of the cloud layer remains relatively constant.

Smith, David A.; Georgantopoulos, Ioannis; Warwick, Robert S.

2000-01-01

101

Results from a deep RXTE/PCA scan across the Galactic plane  

NASA Astrophysics Data System (ADS)

We present the results of deep scans across the Galactic plane that were performed with RXTE/PCA in 2010-2011. We studied the stripe from bII = 0° to bII = -30° at lII ? 18.°5. We show that the variance of the cosmic X-ray background (CXB) at angular scales ˜1 deg2 is approximately 5 per cent, which is compatible with the variance expected from Poisson variations of a number of discrete sources within the considered field of view. We estimate the cumulative fractional emissivity of the Galactic ridge X-ray emission (GRXE) as (3.0 ± 0.3) × 1027 erg s-1 M?-1 in the energy band 2-10 keV. We do not detect significant variations of the GRXE energy spectrum over the studied latitudes, which might be expected if the GRXE consists of contributions of sources with very different characteristic ages and scaleheights. Making use of ROSAT/PSPC/R7 data, collected within the stripe of our study, we estimate the cumulative emissivity of GRXE sources in the energy band 0.5-2 keV as ˜8 × 1027 erg s-1 M?-1; however, this estimate is subject to uncertainties owing to low-accuracy correction for interstellar photo-absorption. At Galactic latitudes -12° to -18° we detect ˜6-8 degrees size contributionfrom the hot plasma component, with the effective temperature ˜1.6 keV significantly exceeding that usually known for the soft X-ray Galactic background. Its surface brightness is higher than that of any other Galactic components at energies 1-2 keV and gives up to ˜20 per cent of the CXB at these energies. Accounting for such emission is of vital importance, for example, in studies of the emission of clusters of galaxies at their virial radii.

Revnivtsev, Mikhail G.; Molkov, Sergey V.

2012-08-01

102

An Expanded RXTE Survey of Long-Term X-ray Variability in Seyfert 1 Galaxies  

NASA Technical Reports Server (NTRS)

The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogenous samples of 2-12 keV light curves, probing hard X-ray variability on successively longer durations from approx. 1 day to approx. 3.5 years. 2-10 keV variability on time scales of approx. 1 day, as probed by ASCA, are included. All sources exhibit stronger X-ray variability towards longer time scales, with variability amplitudes saturating at the longest time scales, but the increase is greater for relatively higher luminosity sources. The well-documented anticorrelation between variability amplitude and luminosity is confirmed on all time scales. However, anticorrelations between variability amplitude and black hole mass estimate are evident on only the shortest time scales probed. The data are consistent with the models of power spectral density (PSD) movement described in Markowitz et al. (2003) and McHardy et al. (2004), whereby Seyfert 1 galaxies variability can be described by a single, universal PSD shape whose cutoff frequency scales with black hole mass. The best-fitting scaling relations between variability time scale, black hole mass and X-ray luminosity support an average accretion rate of 2% of the Eddington limit for the sample. Nearly all sources exhibit stronger variability in the relatively soft 2-4 keV band compared to the 7-12 keV band on all time scales. Color-flux diagrams support also Seyfert 1s' softening as they brighten. There are indications that relatively less luminous or less massive sources exhibit a greater degree of spectral variability for a given increase in overall flux.

Markowitz, A.; Edelson, R.

2004-01-01

103

Twelve and a Half Years of Observations of Centaurus A with RXTE  

NASA Technical Reports Server (NTRS)

The Rossi X-ray Timing Explorer has observed the nearest radio galaxy, Centaurus A, in 13 intervals from 1996 August to 2009 February over the 3 - 200 keV band. Spectra accumulated over the 13 intervals were well described with an absorbed power law and an iron line. Cut-off power laws and Compton reflection from cold matter did not provide a better description. For the 2009 January observation we set a lower limit on the cutoff energy at over 2 MeV. The power spectral density function was generated from RXTE/ASM and PCA data as well as an XMM-Newton long look, and clear evidence for a break at 18(+18/-7) days (68% conf.) was seen. Given Cen A's high black hole mass and very low value of L(sub x)/L(sub Edd), the break was a factor of 17+/-9 times higher than the break frequency predicted by the McHardy and coworkers relation, which was empirically derived for a sample of objects, which are radio-quiet and accreting at relatively high values of L(sub bol)/L(sub Edd). We have interpreted our observations in the context of a clumpy molecular torus. The variability characteristics and the broadband spectral energy distribution, when compared to Seyferts, imply that the bright hard X-ray continuum emission may originate at the base of the jet, yet from behind the absorbing line of sight material, in contrast to what is commonly observed from blazars.

Rothschild, R. E.; Markowitz, A.; Rivers, L.; Suchy, S.; Pottschmidt, K.; Kadler, M.; Mueller, C.; Wilms, J.

2011-01-01

104

Chandra and RXTE studies of the X-ray/gamma-ray millisecond pulsar PSR J0218+4232  

NASA Astrophysics Data System (ADS)

We report on high-resolution spatial and timing observations of the millisecond pulsar PSR J0218+4232 performed with the Chandra X-ray Observatory (CXO) and the Rossi X-ray Timing Explorer (RXTE). With these observations we were able to study: a) the possible spatial extent at X-ray energies of the DC source coincident with PSR J0218+4232 in detail (CXO), b) the relative phasing between the X-ray, radio and gamma-ray profiles (CXO and RXTE) and c) the spectral properties at energies beyond 10 keV (RXTE). We found no indications for extended emission at X-ray energies down to about 1" scales and confirmed the presence of a point-like DC-component. The two non-thermal pulses in the X-ray profile are found to be aligned with two of the three pulses visible at radio-frequencies, and more importantly, with the two gamma-ray pulses seen in the EGRET 100-1000 MeV pulse profile. The latter yields now a random occurrence probability for the detection of the gamma-ray signal of about 10-6, which corresponds to a 4.9 sigma detection significance. This strenghtens the credibility of our earlier claimed detection of pulsed high-energy gamma-ray emission from this millisecond pulsar. The pulsed spectrum extends to about 20 keV and can be described by a power-law with photon index of 1.14, slightly softer than measured by the BeppoSAX and XMM for energies below 10 keV. The hard spectrum at X-ray energies and the soft spectrum at high gamma-ray energies is similar to that of Unidentified Gamma-Ray Sources (UGS). Therefore, fast millisecond pulsars with hard X-ray spectra seem to be promising candidates for an UGS association.

Kuiper, L.; Hermsen, W.; Stappers, B.

2003-07-01

105

X-ray outburst of the symbiotic star CI Cam/XTE J0421+560: RXTE observations  

NASA Astrophysics Data System (ADS)

The RXTE observations of the X-ray transient XTE J0421+560/CI Cam in early April 1998 are presented. The all-sky monitor (ASM) light curve exhibits an unusually rapid decline in the object's luminosity. The PCA and HEXTE spectra taken during a series of observations of the object are analyzed in detail. Two emission lines at energies ~6.5 and 8 keV were detected. The possibility of the observed X-ray emission being generated in a relativistic plasma jet is considered. An analogy with the well-known Galactic source SS 433 is noted.

Revnivtsev, M. G.; Emel'Yanov, A. N.; Borozdin, K. N.

1999-05-01

106

RXTE Observations of 0.1-300 Hz QPOs in the Microquasar GRO J1655-40  

Microsoft Academic Search

We have investigated 52 RXTE pointed observations of GRO J1655-40 spanning\\u000athe X-ray outburst that commenced on 1996 April 25 and lasted for 16 months.\\u000aOur X-ray timing analyses reveal four types of QPOs: three with relatively\\u000astable central frequencies at 300 Hz, 9 Hz, and 0.1 Hz, and a fourth that\\u000avaried over the range 14-28 Hz. The 300

Ronald A. Remillard; Edward H. Morgan; Jeffrey E. McClintock; Charles D. Bailyn; J. A. Orosz

1998-01-01

107

RXTE/ASM observations of new superbursts from Ser X-1 and 4U 1636-536  

NASA Astrophysics Data System (ADS)

A systematic search for superbursts in the RXTE/ASM archive up to June 2009 of all type I X-ray bursters known to date revealed previously unnoticed long- duration events. Two candidate superbursts were found in ASM data of Ser X-1. One superburst was previously known for this source (Cornelisse et al. 2002, A&A 382, 174). The new ones occurred on 1999 Aug 9 (MJD 51399) and 2008 Oct 14 (MJD 54753).

Kuulkers, Erik

2009-07-01

108

RXTE PCA Detection of a New Outburst of XTE J1728-295 (probably IGR J17285-2922)  

NASA Astrophysics Data System (ADS)

We report the detection of a new outburst of a source designated XTE J1728-295 in the RXTE PCA scans, which is probably the same as IGR J17285-2922. This source was first detected in August-October 2003 with PCA scans of the galactic center region, and is speculated to be a black hole candidate (Barlow et al. 2005, A&A, 437, L27). In PCA scans on 2010-08-28 near 09:35 UTC, the source rose to a flux of 6.5 mCrab (2-10 keV).

Markwardt, Craig B.; Swank, Jean H.

2010-08-01

109

RXTE Observation of 4U 1630-47 During its 1998 Outburst  

NASA Technical Reports Server (NTRS)

During the 1998 outburst of 4U 1630-47 it was extensively observed with the Rossi X-ray Timing Explorer (RXTE). In order to cover the outburst more thoroughly our data (Obs. ID: 30178-0[1-2]- ) were combined with those of Cui et al. (Obs. ID: 30188-02-). These observations were later compared with the complementary observations. Power density and energy spectra have been made for each observation. The data was used to place radio and hard X-ray observations within context. Analysis of SAX (Satellite per Astronomia a raggi X) and BATSE (Burst and Transient Source Experiment) data was also included within the study. The count rate and position in hardness-intensity, color-color diagrams and simple spectral fits are used to track the concurrent spectral changes. The source showed seven distinct types of timing behavior, most of which show differences with the canonical black hole spectral/timing states. In marked contrast to previous outbursts, we find quasi-periodic oscillation (QPO) signals during nearly all stages of the outburst with frequencies between 0.06 Hz and 14 Hz and a remarkable variety of other characteristics. In particular we find large (up to 23% rms) amplitude QPO on the early rise. Later, slow 0.1 Hz semi- regular short (- 5 sec), 9 to 16% deep dips dominate the light curve. At this time there are two QPOS, one stable near 13.5 Hz and the other whose frequency drops from 6-8 Hz to - 4.5 Hz during the dips. BeppoSAX observations during the very late declining phase show 4U 1630-47 in a low state. These results will shortly be published. We are completing a detailed analysis of the energy spectra (in preparation). The QPO/noise properties are being correlated with the concurrent spectral changes. Detailed studies of the QPO are being undertaken using sophisticated timing analysis methods. Finally a comparison with the other outbursts of 1630-47 is being made.

Dieters, Stefan W.

1999-01-01

110

Measuring the broad-band power spectra of active galactic nuclei with RXTE  

NASA Astrophysics Data System (ADS)

We develop a Monte Carlo technique to test models for the true power spectra of intermittently sampled light curves against the noisy, observed power spectra, and produce a reliable estimate of the goodness of fit of the given model. We apply this technique to constrain the broad-band power spectra of a sample of four Seyfert galaxies monitored by the Rossi X-ray Timing Explorer (RXTE ) over three years. We show that the power spectra of three of the AGN in our sample (MCG-6-30-15, NGC 5506 and NGC 3516) flatten significantly towards low frequencies, while the power spectrum of NGC 5548 shows no evidence of flattening. We fit two models for the flattening: a `knee' model, analogous to the low-frequency break seen in the power spectra of BHXRBs in the low state (where the power-spectral slope flattens to ? =0), and a `high-frequency break' model (where the power-spectral slope flattens to ? =1), analogous to the high-frequency break seen in the high- and low-state power spectra of the classic BHXRB Cyg X-1. Both models provide good fits to the power spectra of all four AGN. For both models, the characteristic frequency for flattening is significantly higher in MCG-6-30-15 than in NGC 3516 (by a factor of ~10), although both sources have similar X-ray luminosities, suggesting that MCG-6-30-15 has a lower black hole mass and is accreting at a higher rate than NGC 3516. Assuming linear scaling of characteristic frequencies with black hole mass, the high accretion rate implied for MCG-6-30-15 favours the high-frequency break model for this source, and further suggests that MCG-6-30-15, and possibly NGC 5506, may be analogues of Cyg X-1 in the high state. Comparison of our model fits with naive fits, where the model is fitted directly to the observed power spectra (with errors estimated from the data), shows that Monte Carlo fitting is essential for reliably constraining the broad-band power spectra of AGN light curves obtained to date.

Uttley, P.; McHardy, I. M.; Papadakis, I. E.

2002-05-01

111

Experience Gained From Launch and Early Orbit Support of the Rossi X-Ray Timing Explorer (RXTE)  

NASA Technical Reports Server (NTRS)

this paper reports the results to date of early mission support provided by the personnel of the Goddard Space Flight Center Flight Dynamics Division (FDD) for the Rossi X-Ray Timing Explorer (RXTE) spacecraft. For this mission, the FDD supports onboard attitude determination and ephemeris propagation by supplying ground-based orbit and attitude solutions and calibration results. The first phase of that support was to provide launch window analyses. As the launch window was determined, acquisition attitudes were calculated and calibration slews were planned. postlaunch, these slews provided the basis for ground determined calibration. Ground determined calibration results are used to improve the accuracy of onboard solutions. The FDD is applying new calibration tools designed to facilitate use of the simultaneous, high-accuracy star observations from the two RXTE star trackers for ground attitude determination and calibration. An evaluation of the performance of these tools is presented. The FDD provides updates to the onboard star catalog based on preflight analysis and analysis of flight data. The in-flight results of the mission support in each area are summarized and compared with pre-mission expectations.

Fink, D. R.; Chapman, K. B.; Davis, W. S.; Hashmall, J. A.; Shulman, S. E.; Underwood, S. C.; Zsoldos, J. M.; Harman, R. R.

1996-01-01

112

RXTE Observations of the 1A 1118-61 in an Outburst, and the Discovery of a Cyclotron Line  

NASA Technical Reports Server (NTRS)

We present the analysis of RXTE monitoring data obtained during the January 2009 outburst of the hard X-ray transient IA 1118-61. Using these observations the broadband (3.5-120 keV) spectrum of the source was measured for the first time ever. We have found that the broadband continuum spectrum of the source is similar to other accreting pulsars and is well described by several conventionally used phenomenological models. We have discovered that regardless of the applied continuum model, a prominent broad absorption feature at approx. 55 keV is observed. We interpret this feature as a Cyclotron Resonance Scattering Feature (CRSF). The observed CRSF energy is one of the highest known and corresponds to a magnetic field of B approx. 4.8 x 10(exp 12) G in the scattering region. Furthermore, our data suggests an iron emission line presence, which was not reported previously for lA 1118-61 as well. Timing properties of the source, including a strong spin-up, were found to be similar to those observed by CGRO/BATSE during the previous outburst, however the broadband capabilities of RXTE reveal a more complicated energy dependency of the pulse-profile.

Doroshenko, V.; Suchy, S.; Santangelo, A; Staubert, R.; Kreykenbohm, I.; Rothschild, R.; Pottschmidt, K.; Wilms, J.

2010-01-01

113

RXTE and BeppoSAX Observations of MCG-5-23-16: Reflection From Distant Cold Material  

NASA Technical Reports Server (NTRS)

We examine the spectral variability of the Seyfert 1.9 galaxy MCG-5-23-16 using RXTE and BeppoSAX observations spanning 2 years from April 1996 to April 1998. During the first year the X-ray source brightens by a factor of approximately 25% on timescales of days to months. During this time, the reprocessed continuum emission seen with RXTE does not respond measurably to the continuum increase. However, by the end of the second year during the BeppoSAX epoch the X-ray source has faded again. This time, the reprocessed emission has also faded, indicating that the reprocessed flux has responded to the continuum. If these effects are caused by time delays due to the distance between the X-ray source and the reprocessing region, we derive a light crossing time of between approximately 1 light day and approximately 1.5 light years. This corresponds to a distance of 0.001 pc to 0.55 pc, which implies that the reprocessed emission originates between 3 x 10(exp 15) cm and 1.6 x 10(exp l8) cm from the X-ray source. In other words, the reprocessing in MCG-5-23-16 is not dominated by the inner regions of a standard accretion disk.

Mattson, B. J.; Weaver, K. A.

2003-01-01

114

An RXTE Archival Search for Coherent X-ray Pulsations in LMXB 4U 1820-30  

NASA Astrophysics Data System (ADS)

As part of a large-scale search for coherent pulsations from LMXBs in the RXTE archive, we have completed a detailed series of searches for coherent pulsations of 4U 1820-30 - an ultracompact LMXB with a binary period of 11.4 minutes located in the globular cluster NGC 6624. The small binary period leads to a very high acceleration, so we used phase modulation searches as well as acceleration searches to give significant sensitivity to millisecond pulsations. We searched a total of 34 archival RXTE observations, 32 of which had an on-source integration time longer than 10 ks, and some of which were made consecutively which allowed us to combine them. While we found no pulsations, we have been able to place the first stringent (95% confidence) pulsed fraction limits of <~0.8% for all realistic spin frequencies (i.e. <~1 kHz) and likely companion masses (0.02 Msolar <= Mc <= 0.3 Msolar). By contrast all five LMXBs known to emit coherent pulsations have intrinsic pulsed fractions in the range 3% to 7% when pulsations are observed.

Dib, Rim; Ransom, Scott; Ray, Paul; Kaspi, Victoria

2004-07-01

115

Excite Travel  

NSDL National Science Digital Library

Excite Travel is one of the most comprehensive international guides to communities around the world. Excite Travel provides easy and timely access to information on travel, entertainment, and local business, plus government and community services for all regions of the world.

1998-01-01

116

RXTE Observations of Anomalous X-ray Pulsar 1E 1547.0-5408 During and After its 2008 and 2009 Outbursts.  

National Technical Information Service (NTIS)

We present the results of Rossi X-ray Timing Explorer (RXTE) and Swift monitoring observations of the magnetar 1E 1547.0-5408 following the pulsar's radiative outbursts in 2008 October and 2009 January. We report on a study of the evolution of the timing ...

F. P. Gavriil P. Scholz R. Dib V. M. Kaspi

2012-01-01

117

Building Teamwork through Science  

ERIC Educational Resources Information Center

This article discusses how children can build teamwork through science activities. Through science experiences, the excitement can generate a sense of shared community in class. Science experiments help develop children's learning. Science experiences are a prime source of powerful new words because they use a common language to describe the…

Rivkin, Mary

2005-01-01

118

On neutron star mass-radius relation and distance determination for Cyg X-2: RXTE observations and theory  

NASA Astrophysics Data System (ADS)

Determination of masses and radii of neutron stars is one of the most crucial tasks of contemporary observational astronomy as long as it can provide important information about the state of matter inside compact stars. Thermonuclear flashes at bottoms of neutron stars referred to as Type I X-ray bursts, can reveal characteristics of central object provided that appropriate observational data and analysis techniques are present. Analytic theory of expansion and contraction stages of X-ray burster has been developed which provided spectral shapes and hardening/softening factors for emerging X-ray radiation. Gravitational effects and photon diffusion are assumed along with Comptonization and emission-absorption processes are accounted for. Until the advent of Rossi X-ray Timing Explorer (RXTE) the X-ray data suffered from low counting statistics and insufficient time resolution to permit studying temporal evolution of X-ray bursters in details and putting close constraints on the mass-radius relationship. Increased spectral quality and outstanding time resolution of RXTE data coupled with accuracy of the analytical description allow us to narrow constraints on neutron star mass and radius. We present the further development of analytical theory and the results of applying it to X-ray bursts from number of sources, observed with RXTE. More than 10 Type I X-ray bursts were detected from Cygnus X-2, some of which show photospheric radius expansion. We investigate this set of data to obtain tight constraints on mass and radius of the neutron star. One important application of our results is to test the kilohertz QPO models. Interpretation of microsecond variability in Cygnus X-2 and other LMXBs as the frequency of the minimum stable orbit led to the conclusion that neutron stars may have masses well above 1.4 solar masses. Our spectral analysis of Type I X-ray bursts in Cyg X-2 with taking into account all radiative transfer and General Relativity effects does not confirm the the mass-radius estimates derived from the last stable orbit model. We obtained the mass constraints within 1.4 +/- 0.2 solar masses, radius within 10 +/- 0.5 km and we found that 10 kpc for the distance to the source is consistent with the observations.

Titarchuk, Lev; Shaposhnikov, Nickolai

2002-04-01

119

Excite Assistant  

NSDL National Science Digital Library

Just when the concept of "push" technology seems like yesterday's news, Excite, Inc. produces a handy little program, the Excite Assistant, that pushes data to you without being pushy. The Excite Assistant provides you with instant access to various types of up-to-date information such as the weather for your area, the broadcast TV shows on at the moment, updated stock quotes, your horoscope, and more. The information is summarized within the Assistant's window, but when an item requires expansion, your browser is launched. By far the most useful aspect of this program is the mail notification feature. If you use Excite's Web-based mail service, the Excite Assistant, if active, will play a sound and it's icon will blink when new mail arrives. The Assistant will display the subject line and who the mail is from; clicking on the new mail loads it in your browser. Excite Assistant runs on Win95/98/NT and is free but does display small ads.

120

Comprehensive Analysis of RXTE Data from Cyg X-1. Spectral Index-Quasi-Periodic Oscillation Frequency-Luminosity Correlations  

NASA Technical Reports Server (NTRS)

We present timing and spectral analysis of approx. 2.2 Ms of Rossi X-ray Time Explorer (RXTE) archival data from Cyg X-1. Using the generic Comptonization model we reveal that the spectrum of Cyg X-1 consists of three components: a thermal seed photon spectrum, a Comptonized part of the seed photon spectrum and the iron line. We find a strong correlation between 0.1-20 Hz frequencies of quasiperiodic oscillations (QPOs) and the spectral power-law index. Presence of two spectral phases (states) are clearly seen in the data when the spectral indices saturate at low and high values of QPO frequencies. This saturation effect was discovered earlier in a number of black hole candidate (BHC) sources and now we strongly confirm this phenomenon in Cyg X-1. In the soft state this index- QPO frequency correlation shows a saturation of the photon index Gamma approx. 2.1 at high values of the low frequency upsilon(sub L). The saturation level of Gamma approx. 2.1 is the lowest value found yet in BHCs. The bolometric luminosity does not show clear correlation with the index. We also show that Fe K(sub alpha) emission line strength (equivalent width, EW) correlates with the QPO frequency. EW increases from 200 eV in the low/hard state to 1.5 keV in the high/soft state. The revealed observational correlations allow us to propose a scenario for the spectral transition and iron line formation which occur in BHC sources. We also present the spectral state (the power-law index) evolution for eight years of Cyg X-1 observations by RXTE.

Shaposhnikov, Nickolai; Titarchuk, Lev

2006-01-01

121

The Nature of the X-Ray Binary IGR J19294+1816 from INTEGRAL, RXTE, and Swift Observations  

NASA Technical Reports Server (NTRS)

We report the results of a high-energy multi-instrumental campaign with INTEGRAL, RXTE, and Swift of the recently discovered INTEGRAL source IGR J19294+ 1816. The Swift/XRT data allow us to refine the position of the source to R.A. (J2000) = 19h 29m 55.9s, Decl. (J2000) = +18 deg 18 feet 38 inches . 4 (+/- 3 inches .5), which in turn permits us to identify a candidate infrared counterpart. The Swift and RXTE spectra are well fitted with absorbed power laws with hard (Gamma approx 1) photon indices. During the longest Swift observation, we obtained evidence of absorption in true excess to the Galactic value, which may indicate some intrinsic absorption in this source. We detected a strong (P = 40%) pulsations at 12.43781 (+/- 0.00003) s that we interpret as the spin period of a pulsar. All these results, coupled with the possible 117 day orbital period, point to IGR J19294+ 1816 being an high-mass X-ray binary (HMXB) with a Be companion star. However, while the long-term INTEGRAL/IBIS/ISGRI 18-40 keV light curve shows that the source spends most of its time in an undetectable state, we detect occurrences of short (2000-3000 s) and intense flares that are more typical of supergiant fast X-ray transients. We therefore cannot make firm conclusions on the type of system, and we discuss the possible implication of IGR J19294+1816 being an Supergiant Fast X-ray Transient (SFXT).

Rodriquez, J.; Tomsick, J. A.; Bodaghee, A.; ZuritaHeras, J.-A.; Chaty, S.; Paizis, A.; Corbel, S.

2009-01-01

122

The X-ray source GRS 1915 + 105: The low-luminosity state and transitions between the states during 1996-1997 (RXTE observations)  

Microsoft Academic Search

We present observations of GRS1915+105 with the instruments of the RXTE (Rossi X-ray Timing Explorer) X-ray Observatory from October 1996 through April 1997, when the source exhibited transitions between the states with high and low X-ray luminosities. With the exception of some individual features, the general temporal and spectral characteristics of the X-ray emission from GRS1915+105 and the pattern of

S. P. Trudolyubov; E. M. Churazov; M. R. Gilfanov

1999-01-01

123

Hard X-ray\\/soft -ray Characteristics of the Persistent Emission from Magnetars - Results based on multi-year INTEGRAL, RXTE and XMM Newton observations  

Microsoft Academic Search

In this paper the current status of high-energy research on the hard X-ray characteristics of the per- sistent emission from magnetars is reviewed. Focus is put on recent intriguing results for 1RXS J1708-40 from phase resolved spectral analysis over a 2 decades wide energy band (? 3 ? 300 keV) combining con- temporaneous RXTE, XMM and INTEGRAL data. For 1E

L. Kuiper; P. R. den Hartog; W. Hermsen

124

RXTE Detection of an 85.4 s X-ray Pulsar in the Direction of the SMC (SXP 85.4)  

Microsoft Academic Search

RXTE PCA observations in the direction of the Small Magellanic Cloud made on 2010-08-16 and 2010-08-21, as part of a long-term monitoring program, show the presence of pulsations with a period of 85.4 ± 0.1 s. The modulation semi-amplitude on 2010-08-21 was approximately 0.15 cts\\/s\\/PCU. This period does not coincide with the fundamental period of any known pulsar in the

R. H. D. Corbet; E. S. Bartlett; M. J. Coe; V. A. McBride; L. J. Townsend; M. P. E. Schurch; F. E. Marshall

2010-01-01

125

RXTE X-ray monitoring of the supermassive star eta carinae: Colliding wind emission in a pre-hypernova candidate binary?  

Microsoft Academic Search

ROSAT, ASCA, RXTE and now Chandra X-ray observations of the supermassive star ? Carinae obtained over the past 7 years chronicle the inordinate variability of the high-energy emission. The most important characteristics are these: 1) the hard X-ray ``low state'' evidently recurs with a period consistent with the ``Damineli Cycle'' of 5.5 years; 2) the X-ray emission exhibits ``flares'' which

M. F. Corcoran; A. C. Fredericks; R. Petre; J. H. Swank; S. A. Drake; K. Davidson; K. Ishibashi; S. White; A. Damineli

2000-01-01

126

Structure of the Circumnuclear Region of Seyfert 2 Galaxies Revealed by RXTE Hard X-Ray Observations of NGC 4945  

NASA Technical Reports Server (NTRS)

NGC 4945 is one of the brightest Se.yfert galaxies on the sky at 100 keV, but is completely absorbed below 10 keV, implying an optical depth of the absorber to electron scattering of a few; its absorption column is probably the largest which still allows a direct view of the nucleus at hard X-ray energies. Our observations of it with the Rossi X-ray Timing Explorer (RXTE) satellite confirm the large absorption, which for a simple phenomenological fit using an absorber with Solar abundances implies a column of 4.5(sup 0.4, sub -0.4) x 10(exp 24) /sq cm. Using a a more realistic scenario (requiring Monte Carlo modeling of the scattering), we infer the optical depth to Thomson scattering of approximately 2.4. If such a scattering medium were to subtend a large solid angle from the nucleus, it should smear out any intrinsic hard X-ray variability on time scales shorter than the light travel time through it. The rapid (with a time scale of approximately a day) hard X-ray variability of NGC 4945 we observed with the RXTE implies that the bulk of the extreme absorption in this object does not originate in a parsec-size, geometrically thick molecular torus. Limits on the amount of scattered flux require that the optically thick material on parsec scales must be rather geometrically thin, subtending a half-angle < 10 deg. This is only marginally consistent with the recent determinations of the obscuring column in hard X-rays, where only a quarter of Seyfert 2s have columns which are optically thick, and presents a problem in accounting for the Cosmic X-ray Background primarily with AGN possessing the geometry as that inferred by us. The small solid angle of the obscuring material, together with the black hole mass (of approximately 1.4 x 10(exp 6) solar mass) from megamaser measurements. allows a robust determination of the source luminosity, which in turn implies that the source radiates at approximately 10% of the Eddington limit.

Madejski, G.; Zycki, P.; Done, C.; Valinia, A.; Blanco, P.; Rothschild, R.; Turek, B.

2000-01-01

127

Excited Delirium  

PubMed Central

Excited (or agitated) delirium is characterized by agitation, aggression, acute distress and sudden death, often in the pre-hospital care setting. It is typically associated with the use of drugs that alter dopamine processing, hyperthermia, and, most notably, sometimes with death of the affected person in the custody of law enforcement. Subjects typically die from cardiopulmonary arrest, although the cause is debated. Unfortunately an adequate treatment plan has yet to be established, in part due to the fact that most patients die before hospital arrival. While there is still much to be discovered about the pathophysiology and treatment, it is hoped that this extensive review will provide both police and medical personnel with the information necessary to recognize and respond appropriately to excited delirium.

Takeuchi, Asia; Ahern, Terence L.; Henderson, Sean O.

2011-01-01

128

NASA and Mary J. Blige Encourage Exciting Careers For Women  

NASA Video Gallery

NASA is collaborating with award-winning recording artist Mary J. Blige to encourage young women to pursue exciting experiences and career choices through studying science, technology, engineering ...

129

Excited baryons  

SciTech Connect

The status of the theory of the low-energy approach to hadron structure is reviewed briefly by surveying a few relevant models. A few examples of tests needed to sort out the predictions of different models pertaining to the quark-gluon structure of hadrons are discussed, and given the resulting physics objectives, a few experimental options for excited baryon research at CFBAF are suggested. (LEW)

Mukhopadhyay, N.C.

1986-01-01

130

RXTE Timing and Spectroscopy of a Black Hole X-Ray Binary in Outburst  

NASA Technical Reports Server (NTRS)

This program was executed primarily to observe the black hole transient GX339-4. Observations were made simultaneously with XMM-Newton in 2004 March, and observations simultaneous with Chandra will continue to be made in the fall of 2004. As the total data set has not yet been obtained, a great deal of work remains. Preliminary examination of the data has shown extremely exciting spectral features (Fe K-alpha emission lines) and timing features (strong QPOs and flaring variability) of exactly the sort we hoped to obtain. We expect that the results of these observations will be finalized over the next year. The results will be presented in 2-3 publications in refereed journals. We have requested a no-cost extension of this grant to analyze and report our findings.

Miller, Jon M.

2004-01-01

131

Step Right Up To the Science Carnival.  

ERIC Educational Resources Information Center

Describes a science carnival where children and adults share in the excitement of the carnival atmosphere and participate in doing science together. Discusses creating a carnival, gathering ideas, traditional booth redesign, and science topic booths. (JRH)

Cooper, Doug

1997-01-01

132

Monitoring the Violent Activity from the Inner Accretion Disk of the Seyfert 1.9 Galaxy NGC 2992 with RXTE  

NASA Technical Reports Server (NTRS)

We present the results of a one year monitoring campaign of the Seyfert 1.9 galaxy NGC 2992 with RXTE. Historically, the source has been shown to vary dramatically in 2-10 keV flux over timescales of years and was thought to be slowly transitioning between periods of quiescence and active accretion. Our results show that in one year the source continuum flux covered almost the entire historical range, making it unlikely that the low-luminosity states correspond to the accretion mechanism switching off. During flaring episodes we found that a highly redshifted Fe K line appears, implying that the violent activity is occurring in the inner accretion disk, within 100 gravitational radii of the central black hole. We also found that the Compton y parameter for the X-ray continuum remained approximately constant during the large amplitude variability. These observations make NGC 2992 well-suited for future multi-waveband monitoring, as a test-bed for constraining accretion models.

Mruphy, Kendrah D.; Yaqoob, Tahir; Terashima, Yuichi

2007-01-01

133

RXTE and BeppoSAX Observations of the Transient X-ray Pulsar XTE J 18591+083  

NASA Technical Reports Server (NTRS)

We present observations of the 9.8 s X-ray pulsar XTE J159+083 made with the All-Sky Monitor (ASM) and Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer (RXTE), and the Wide Field Cameras (WFC) on board BeppoSAX. The ASM data cover a 12 year time interval and show that an extended outburst occurred between approximately MJD50, 250, and 50, 460 (1996 June 16 to 1997 January 12). The ASM data excluding this outburst interval suggest a possible 61 day modulation. Eighteen sets of PCA observations were obtained over an approx. one month interval in 1999. The flux variability measured with the PCA appears consistent with the possible period found with the ASM. The PCA measurements of the pulse period showed it to decrease non-monotonically and then to increase significantly. Doppler shifts due to orbital motion rather than accretion torques appear to be better able to explain the pulse period changes. Observations with the WFC during the extended outburst give an error box which is consistent with a previously determined PCA error box but is significantly smaller. The transient nature of XTE J1859+083 and the length of its pulse period are consistent with it being a Be/neutral star binary. The possible 61 day orbital period would be of the expected length for a Be star system with a 9.8 s pulse period.

Corbet, R. H. D.; intZand, J. J. M.; Levine, A. M.; Marshall, F. E.

2008-01-01

134

RXTE, VLBA, Optical, and Radio Monitoring of the Quasars 3C 279, PKS 1510--089, and 3C 273  

NASA Technical Reports Server (NTRS)

We are continuing our combined RXTE X-ray, VLBA imaging (at 43 GHz), optical (several observatories), and radio (University of Michigan Radio Astronomy Observatory) monitoring of the quasars 3C 279 and PKS 1510-089, and have started similar monitoring of 3C 273. X-ray flares in 3C 279 and PKS 1510-089 are associated with ejections of superluminal components. In addition, there is a close connection between the optical and X-ray variability of 3C 279. There is a strong correlation between the 14.5 GHz and X-ray variability of PKS 1510-089 in 1997 and 1998 (with the radio leading the X-ray) that becomes weaker in subsequent years. X-ray fluctuations occur on a variety of timescales in 3C 273, with a major prolonged outburst in mid-2001. The lead author will discuss the correlations in terms of inverse Compton models for the X-ray emission coupled with synchrotron models for the lower-frequency radiation. Synchrotron self-Compton models can explain the "reverse" time lag in PKS 1510-089 is well as the variable correlation between the X-ray variations and those at lower frequencies in this object and in 3C 279.

Marscher, A. P.; Jorstad, S. G.; Aller, M. F.; McHardy, I. M.; Balonek, T. J.

2001-01-01

135

The Discovery Outburst of the X-Ray Transient IGR J17497-2821 Observed with RXTE and ATCA  

NASA Technical Reports Server (NTRS)

We report the results of a series of RXTE and ATCA observations of the recently discovered X-ray transient IGR J17497-2821. Our 3-200 keV PCA+HEXTE spectral analysis shows very little variations over a period of approx.10 days around the maximum of the outburst. IGR J17497-2821 is found in a typical low-hard state (LHS) of X-ray binaries (XRBs), well represented by an absorbed Comptonized spectrum with an iron edge at about 7 keV. The high value of the absorption (approx.4 x 10(exp 22/sq cm suggests that the source is located at a large distance, either close to the Galactic center or beyond. The timing analysis shows no particular features, while the shape of the power density spectra is also typical of the LHS of XRBs, with apprrox.36% rms variability. No radio counterpart is found down to a limit of 0.21 mJy at 4.80 and 8.64 GHz. Although the position of IGR J17497-2821 in the radio to X-ray flux diagram is well below the correlation usually observed in the LHS of black holes, the comparison of its X-ray properties with those of other sources leads us to suggest that it is a black hole candidate.

Rodriquez, Jerome; Bel, Marion Cadolle; Tomsick, John A.; Corbel, Stephane; Brocksopp, Catherine; Paizis, Ada; Shaw, Simon E.; Bodaghee, Arash

2007-01-01

136

Life Science  

NSDL National Science Digital Library

For decades, many of the nation's life science classrooms have been anything but lively. Biology has been criticized for being content heavy, overloaded with vocabulary, and tested by rote. Six to seven hundred pages of text, presented to teenagers with limited abilities to reason, constituted what in most cases was the only required science in high schools. By contrast, the classroom of a life science teacher who is moving toward the Standards provides an exciting environment for inquiry and a core of content that is smaller but in greater depth than in the past. Topics are covered in more detail, coursework is integrated, and both teachers and students feel challenged. This free selection includes an inquiry-based, life science lesson and the Table of Contents.

2004-01-01

137

News CPD Event: Teaching day gives new perspectives Workshop: IOP network devolops its ideas Conference: Conference offers much to teachers Event: Physics is made easy in Liverpool Communication: IOSTE debates the complexities of STE Conference: Teaching event excites in Exeter Meeting Invitation: Wales physics meeting invites bookings CPD Event: Science teachers get hands on with development Research: Conference highlights liquid crytstal research in teaching Education: Teachers give positive feedback Science Fair: Science fair brings physics to students Teaching: Conference explores trends in teaching Forthcoming events  

NASA Astrophysics Data System (ADS)

CPD Event: Teaching day gives new perspectives Workshop: IOP network devolops its ideas Conference: Conference offers much to teachers Event: Physics is made easy in Liverpool Communication: IOSTE debates the complexities of STE Conference: Teaching event excites in Exeter Meeting Invitation: Wales physics meeting invites bookings CPD Event: Science teachers get hands on with development Research: Conference highlights liquid crytstal research in teaching Education: Teachers give positive feedback Science Fair: Science fair brings physics to students Teaching: Conference explores trends in teaching Forthcoming events

2010-09-01

138

Saturated excitation microscopy with optimized excitation modulation.  

PubMed

Saturated excitation (SAX) microscopy utilizes the nonlinear relation between fluorescence emission and excitation under saturated excitation to improve the spatial resolution of confocal microscopy. In this study, we theoretically and experimentally investigate the saturation of fluorescence excitation under modulated excitation to optimize the excitation conditions for SAX microscopy. Calculation of the relationships between fluorescence and excitation intensity with different modulation frequencies reveals that the lifetime of the triplet state of the fluorescent probe strongly affects the strength of the demodulated fluorescence signals. We also find that photobleaching shows little dependence on the modulation frequency. These investigations allow us to determine the optimum excitation conditions, that is, the conditions providing sufficient fluorescence saturation without strong photobleaching. For a sample stained with ATTO Rho6G phalloidin, we estimate the optimal excitation conditions, which are produced with 50 kHz excitation modulation and a 50 ?sec pixel dwell time, and successfully perform three-dimensional imaging with sub-diffraction resolution. PMID:24488765

Yonemaru, Yasuo; Yamanaka, Masahito; Smith, Nicholas I; Kawata, Satoshi; Fujita, Katsumasa

2014-03-17

139

Estudo espectral em raios-X duros de fontes do tipo Z com o HEXTE/RXTE  

NASA Astrophysics Data System (ADS)

Apresentam-se os resultados de um estudo espectral em raios-X de fontes do tipo Z. As fontes do tipo Z são binárias de raios-X de baixa massa (BXBM) com campo magnético intermediário (B~109G). Esta classe de fontes é composta por apenas 6 fontes Galácticas (a saber: ScoX-1, 9, 7, CygX-2, 5 e 0). A nossa análise se concentra na faixa de raios-X duros (E ~ 20keV), até cerca de 200keV, faixa ótima de operação do telescópio "High Energy X-ray Timing Experiment" (HEXTE), um dos três telescópios de raios-X à bordo do Rossi X-ray Timing Explorer (RXTE). Nossa motivação para tal estudo, uma busca de caudas em raios-X duros em fontes do tipo Z, foi o pouco conhecimento sobre a emissão nesta faixa de energia das referidas fontes quando comparadas, por exemplo, as fontes do tipo atoll (também BXBM). Apresentam-se a análise/redução de dados e explicita-se a maneira como o HEXTE mede o ru1do de fundo. Especial atenção é direcionada a este item devido a localização das fontes do tipo Z e também ao problema de contaminação por fontes próximas. Com exceção de ScoX-1, nenhuma cauda em raios-X duros foi encontrada para as outras fontes, a despeito de resultados de detecção dessas caudas em algumas fontes pelo satélite BeppoSAX. As interpretações deste resultado serão apresentadas. Do ponto de vista deste estudo, nós deduzimos que a produção de caudas de raios-X duros em fontes do tipo Z é um processo disparado quando, pelo menos, uma condição é satisfeita: o brilho da componente térmica do espectro precisa estar acima de um certo valor limiar de ~4´1036ergs-1.

D'Amico, F.; Heindl, W. A.; Rothschild, R. E.

2003-08-01

140

Learning Science through History  

ERIC Educational Resources Information Center

This article discusses how the author has developed and managed a collection of exciting resources that aim to aid transition from primary to secondary school by tackling science topics through historical contexts. Working with teachers at both primary and secondary level, the Double Crossed project has designed two exciting cross-curricular…

Brodie, Eleanor

2010-01-01

141

DISCOVERY AND MONITORING OF A NEW BLACK HOLE CANDIDATE XTE J1752-223 WITH RXTE: RMS SPECTRUM EVOLUTION, BLACK HOLE MASS, AND THE SOURCE DISTANCE  

SciTech Connect

We report on the discovery and monitoring observations of a new galactic black hole (BH) candidate XTE J1752-223 by Rossi X-ray Timing Explorer (RXTE). The new source appeared on the X-ray sky on 2009 October 21 and was active for almost 8 months. Phenomenologically, the source exhibited the low-hard/high-soft spectral state bi-modality and the variability evolution during the state transition that matches standard behavior expected from a stellar mass BH binary. We model the energy spectrum throughout the outburst using a generic Comptonization model assuming that part of the input soft radiation in the form of a blackbody spectrum gets reprocessed in the Comptonizing medium. We follow the evolution of fractional root-mean-square (rms) variability in the RXTE/PCA energy band with the source spectral state and conclude that broadband variability is strongly correlated with the source hardness (or Comptonized fraction). We follow changes in the energy distribution of rms variability during the low-hard state and the state transition, and find further evidence that variable emission is strongly concentrated in the power-law spectral component. We discuss the implication of our results to the Comptonization regimes during different spectral states. Correlations of spectral and variability properties provide measurements of the BH mass and distance to the source. The spectral-timing correlation scaling technique applied to the RXTE observations during the hard-to-soft state transition indicates a mass of the BH in XTE J1752-223 between 8 and 11 solar masses and a distance to the source of about 3.5 kpc.

Shaposhnikov, Nikolai [Department of Astronomy, CRESST/University of Maryland, College Park, MD 20742 (United States); Markwardt, Craig; Swank, Jean; Krimm, Hans, E-mail: nikolai.v.shaposhnikov@nasa.go [Goddard Space Flight Center, NASA, Astrophysics Science Division, Greenbelt MD 20771 (United States)

2010-11-10

142

Discovery and Monitoring of a New Black Hole Candidate XTE J1752-223 with RXTE: Rms Spectrum Evolution, Black Hole Mass, and the Source Distance  

NASA Astrophysics Data System (ADS)

We report on the discovery and monitoring observations of a new galactic black hole (BH) candidate XTE J1752-223 by Rossi X-ray Timing Explorer (RXTE). The new source appeared on the X-ray sky on 2009 October 21 and was active for almost 8 months. Phenomenologically, the source exhibited the low-hard/high-soft spectral state bi-modality and the variability evolution during the state transition that matches standard behavior expected from a stellar mass BH binary. We model the energy spectrum throughout the outburst using a generic Comptonization model assuming that part of the input soft radiation in the form of a blackbody spectrum gets reprocessed in the Comptonizing medium. We follow the evolution of fractional root-mean-square (rms) variability in the RXTE/PCA energy band with the source spectral state and conclude that broadband variability is strongly correlated with the source hardness (or Comptonized fraction). We follow changes in the energy distribution of rms variability during the low-hard state and the state transition, and find further evidence that variable emission is strongly concentrated in the power-law spectral component. We discuss the implication of our results to the Comptonization regimes during different spectral states. Correlations of spectral and variability properties provide measurements of the BH mass and distance to the source. The spectral-timing correlation scaling technique applied to the RXTE observations during the hard-to-soft state transition indicates a mass of the BH in XTE J1752-223 between 8 and 11 solar masses and a distance to the source of about 3.5 kpc.

Shaposhnikov, Nikolai; Markwardt, Craig; Swank, Jean; Krimm, Hans

2010-11-01

143

Helping New Science Teachers  

NSDL National Science Digital Library

The start of a new school year is a challenging and exciting time for any teacher--and a time when beginning teachers particularly need our support. Working with new science teachers in the New Science Teachers' Support Network (NSTSN) has shown the author

Sterling, Donna R.; Frazier, Wendy M.

2009-07-01

144

Science Career Magazine.  

ERIC Educational Resources Information Center

This magazine is designed for teachers and students in junior and senior high schools. It is intended to help students become more aware about what scientists and engineers do, what's new and exciting in the fields of science and engineering, and what satisfactions might be expected from a career in one of the many different areas of science and…

Halsey, Linda B., Ed.; Sweeley, Charles C., Ed.

145

Corona, Jet, and Relativistic Line Models for Suzaku/RXTE/Chandra-HETG Observations of the Cygnus X-1 Hard State  

NASA Technical Reports Server (NTRS)

Using Suzaku and the Rossi X-ray Timing Explorer (RXTE), we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard "low states". Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source passing through the dense phases of the "focused wind" from the mass donating secondary. One of our observations was also simultaneous with observations by the Chandra-High Energy Transmission Grating (HETG). These latter spectra are crucial for revealing the ionized absorption due to the secondary s focused wind. Such absorption is present and must be accounted for in all four spectra. These simultaneous data give an unprecedented view of the 0.8-300 keV spectrum of Cyg X-1, and hence bear upon both corona and X-ray emitting jet models of black hole hard states. Three models fit the spectra well: coronae with thermal or mixed thermal/non-thermal electron populations, and jets. All three models require a soft component that we fit with a low temperature disk spectrum with an inner radius of only a few tens of GM/c2. All three models also agree that the known spectral break at 10 keV is not solely due to the presence of reflection, but each gives a different underlying explanation for the augmentation of this break. Thus whereas all three models require that there is a relativistically broadened Fe line, the strength and inner radius of such a line is dependent upon the specific model, thus making premature line-based estimates of the black hole spin in the Cyg X-1 system. We look at the relativistic line in detail, accounting for the narrow Fe emission and ionized absorption detected by HETG. Although the specific relativistic parameters of the line are continuum-dependent, none of the broad line fits allow for an inner disk radius that is > 40 GM/c(sup 2).

Nowak, Michael A.; Hanke, Manfred; Trowbridge, Sarah N.; Markoff, Sera B.; Wilms, Joern; Pottschmidt, Katja; Coppi, Paolo; Maitra, Dipankar; Davis, Jhn E.; Tramper, Frank

2009-01-01

146

Pulse phase and precession phase resolved spectroscopy of Hercules X-1: studying a representative Main-On with RXTE  

NASA Astrophysics Data System (ADS)

Aims: We performed a detailed pulse phase resolved spectroscopy of the accreting binary X-ray pulsar Her X-1 in the energy range 3.5-75 keV and have established pulse phase profiles for all spectral parameters. For three parameters, the centroid energy of the cyclotron line, the photon index and the flux of the 6.4 keV iron line, we have studied the variation as a function of 35 d phase. Methods: We analyzed RXTE observations of the Main-On of November 2002 using data from the PCA and the HEXTE instruments. Four different time intervals of about ~1 d duration were selected to provide a good coverage of a complete Main-On. The intervals are centered at 35 d phases 0.03, 0.10, 0.15, and 0.20, respectively. Results: All spectral parameters show a strong modulation with pulse phase. While the centroid energy of the cyclotron line follows roughly the shape of the pulse profile, showing higher values close to the peak of the X-ray pulse, both the photon index and the iron line intensity exhibit distinct minima around the peak of the X-ray pulse. With respect to variations of the observed profiles with 35 d phase, we find that there is a clear evolution of the shape of the pulse profiles (flux versus pulse phase), a moderate increase of the maximum cyclotron line energy (found around pulse phase 0.7), but no significant evolution of the shape of the pulse phase profiles of the cyclotron line energy, the spectral power law index or the iron line intensity. Conclusions: The variation of spectral parameters as a function of the pulse phase provides important information about the system: i. the disappearance of the Fe line flux near the highest continuum flux may be an indication of a hollow cone geometry of the accretion structure; ii. the apparent non-dependence of the cyclotron line energy profiles on 35 d phase provides a new possibility to test the model of free precession of the neutron star, proposed to be responsible for the systematic variations in the pulse profiles.

Vasco, D.; Staubert, R.; Klochkov, D.; Santangelo, A.; Shakura, N.; Postnov, K.

2013-02-01

147

Revisit to the RXTE and ASCA Data for GRO J1655-40: Effects of Radiative Transfer in Corona and Color Hardening in the Disk  

NASA Technical Reports Server (NTRS)

The results of spectral modeling of the data for a series of RXTE observations and four ASCA observations of GRO J1655-40 are presented. The thermal Comptonization model is used instead of the power-law model for the hard component of the two-component continuum spectra. The previously reported dramatic variations of the apparent inner disk radius of GRO J1655-40 during its outburst may be due to the inverse Compton scattering in the hot corona. A procedure is developed for making the radiative transfer correction to the fitting parameters from RXTE data and a more stable inner disk radius is obtained. A practical process of determining the color correction (hardening) factor from observational data is proposed and applied to the four ASCA observations of GRO J1655-40. We found that the color correction factor may vary significantly between different observations and the finally corrected physical inner disk radius remains reasonably stable over a large range of luminosity and spectral states.

Zhang, S. Nan; Zhang, Xiaoling; Wu, Xuebing; Yao, Yangsen; Sun, Xuejun; Xu, Haiguang; Cui, Wei; Chen, Wan; Harmon, B. A.; Robinson, C. R.

1999-01-01

148

X-RAY PHASE-RESOLVED SPECTROSCOPY OF PSRs B0531+21, B1509-58, AND B0540-69 WITH RXTE  

SciTech Connect

The Rossi X-Ray Timing Explorer (RXTE) has made hundreds of observations on three famous young pulsars (PSRs) B0531+21 (Crab), B1509-58, and B0540-69. Using the archive RXTE data, we have studied the phase-resolved spectral properties of these pulsars in details. The variation of the X-ray spectrum with phase of PSR B0531+21 is confirmed here much more precisely and more details are revealed than in the previous studies: The spectrum softens from the beginning of the first pulse, turns to harden right at the pulse peak and becomes the hardest at the bottom of the bridge, softens gradually until the second peak, and then softens rapidly. Different from the previous studies, we found that the spectrum of PSR B1509-58 is significantly harder in the center of the pulse, which is also in contrast to that of PSR B0531+21. The variation of the X-ray spectrum of PSR B0540-69 seems similar to that of PSR B1509-58, but with a lower significance. Using about 10 years of data span, we also studied the real time evolution of the spectra of these pulsars, and no significant evolution has been detected. We discuss the constraints of these results on theoretical models of pulsar X-ray emission.

Ge, M. Y.; Lu, F. J.; Qu, J. L.; Zheng, S. J.; Chen, Y.; Han, D. W., E-mail: gemy@mail.ihep.ac.cn [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2012-04-01

149

Science Sampler: Growth Potential  

NSDL National Science Digital Library

Students will enjoy carrying out this exciting and challenging research project that combines science with computers and mathematics to investigate how polyacrylate animals change in size over time when placed in water and aqueous salt solutions. The hands-on activity motivates students and provides them with enjoyable and rewarding science project experiences. Here they have an opportunity to solve a problem and use the science inquiry skills of observing, collecting, organizing, and analyzing data.

Barry, Dana M.; Barry, James F.

2004-04-01

150

National Computational Science Education Consortium (NCSEC)  

NSDL National Science Digital Library

Serving as a national educational computational science clearinghouse, this website offers math and science teachers everywhere an array of online educational tools and exciting teaching modules that can be used in the classroom.

151

Expanding Science Knowledge: Enabled by Nuclear Power  

NASA Technical Reports Server (NTRS)

The availability of Radioisotope Power Sources (RPSs) power opens up new and exciting mission concepts (1) New trajectories available (2) Power for long term science and operations Astonishing science value associated with these previously non-viable missions

Clark, Karla B.

2011-01-01

152

The Balloons Go Up for Science.  

ERIC Educational Resources Information Center

Describes the planning and implementation of a science week intended to raise the awareness of science in an elementary school. Educational requirements included exciting science happenings and concentrated science teaching of a high standard. The week included demonstrations, guest speakers, and schoolwide assemblies. Demonstrations included the…

Fayle, Maureen

1998-01-01

153

Discovery Channel: Science Fair Central  

NSDL National Science Digital Library

The Discovery Channel promotes student participation in science fairs at this appealing, vibrant website. Users can find a terrific, thorough guide to creating science fair projects, including project ideas and lists of books and external web sites for students to utilize during their research. Students can find tip sheets for projects in many science subjects including astronomy, chemistry, and earth science. Educators can discover how to organize a science fair and parents can learn how to get involved with their children's projects. This site is a great way to excite children about science and scientific investigations.

154

Acoustically excited heated jets. 1: Internal excitation  

NASA Technical Reports Server (NTRS)

The effects of relatively strong upstream acoustic excitation on the mixing of heated jets with the surrounding air are investigated. To determine the extent of the available information on experiments and theories dealing with acoustically excited heated jets, an extensive literature survey was carried out. The experimental program consisted of flow visualization and flowfield velocity and temperature measurements for a broad range of jet operating and flow excitation conditions. A 50.8-mm-diam nozzle was used for this purpose. Parallel to the experimental study, an existing theoretical model of excited jets was refined to include the region downstream of the jet potential core. Excellent agreement was found between theory and experiment in moderately heated jets. However, the theory has not yet been confirmed for highly heated jets. It was found that the sensitivity of heated jets to upstream acoustic excitation varies strongly with the jet operating conditions and that the threshold excitation level increases with increasing jet temperature. Furthermore, the preferential Strouhal number is found not to change significantly with a change of the jet operating conditions. Finally, the effects of the nozzle exit boundary layer thickness appear to be similar for both heated and unheated jets at low Mach numbers.

Lepicovsky, J.; Ahuja, K. K.; Brown, W. H.; Salikuddin, M.; Morris, P. J.

1988-01-01

155

High-energy characteristics of the schizophrenic pulsar PSR J1846-0258 in Kes 75. Multi-year RXTE and INTEGRAL observations crossing the magnetar-like outburst  

Microsoft Academic Search

Aims: PSR J1846-0258 is a young rotation-powered pulsar with one of the highest surface magnetic field strengths, located in the centre of SN-remnant Kes-75. In June 2006 a magnetar-like outburst took place. Using multi-year RXTE and INTEGRAL observations covering the epoch of the outburst, we aim to study the temporal and spectral characteristics of PSR J1846-0258 over a broad ~3-300

L. Kuiper; W. Hermsen

2009-01-01

156

Investigating Science with Young Children.  

ERIC Educational Resources Information Center

Teaching science by a process approach is an exciting adventure for both teachers and their students. Process science is an open ended approach, and the direction learning will take place is determined, for the most part, by the children. This method requires that teachers understand how children learn, know the possibilities a topic offers for…

Althouse, Rosemary

157

Planning a Creative Science Curriculum  

ERIC Educational Resources Information Center

A group of science coordinators in the London Borough of Newham decided that they wanted to create an exciting, stimulating and creative curriculum for teaching science across key stages 1 and 2 (5-11 year-olds). They were motivated to do this because they were concerned about an overloaded curriculum, dominated by literacy and numeracy, with…

Iiyambo, Rebekah

2005-01-01

158

Variable neutron star free precession in Hercules X-1 from evolution of RXTE X-ray pulse profiles with phase of the 35-d cycle  

NASA Astrophysics Data System (ADS)

Accretion of matter on to the surface of a freely precessing neutron star (NS) with a complex non-dipole magnetic field can explain the change of X-ray pulse profiles of Her X-1 observed by RXTE with the phase of the 35-d cycle. We demonstrate this using all available measurements of X-ray pulse profiles in the 9-13 keV energy range obtained with the RXTE/Proportional Counter Array (PCA). The measured profiles guided the elaboration of a geometrical model and the definition of locations of emitting poles, arcs and spots on the NS surface which satisfactorily reproduce the observed pulse profiles and their dependence on free precession phase. We have found that the observed trend of the times of the 35-d turn-ons on the O-C diagram, which can be approximated by a collection of consecutive linear segments around the mean value, can be described by our model by assuming a variable free precession period, with a fractional period change of about a few per cent. Under this assumption and using our model, we have found that the times of phase zero of the NS free precession (which we identify with the maximum separation of the brightest spot on the NS surface with the NS spin axis) occur about 1.6 d after the mean turn-on times inside each `stable' epoch, producing a linear trend on the O-C diagram with the same slope as the observed times of turn-ons. We propose that the 2.5 per cent changes in the free precession period that occur on time scales of several to tens of 35-d cycles can be related to wandering of the principal inertia axis of the NS body due to variations in the patterns of accretion on to the NS surface. The closeness of periods of the disc precession and the NS free precession can be explained by the presence of a synchronization mechanism in the system, which modulates the dynamical interaction of the gas streams and the accretion disc with the NS free precession period.

Postnov, K.; Shakura, N.; Staubert, R.; Kochetkova, A.; Klochkov, D.; Wilms, J.

2013-10-01

159

Science in Orbit  

NASA Technical Reports Server (NTRS)

This talk presents the excitement of doing science in space. It reviews some of the effects of the physical adaptations that the body undergoes to the lower gravity of space. It also discusses the role of the scientist in the space environment. It also discusses the potential uses of space development, particularly with the use of the space station.

Weber, Mary Ellen

2005-01-01

160

Science in Science Fiction.  

ERIC Educational Resources Information Center

Offers some suggestions as to how science fiction, especially television science fiction programs such as "Star Trek" and "Star Wars", can be drawn into physics lessons to illuminate some interesting issues. (Author/KHR)

Allday, Jonathan

2003-01-01

161

Excitation of instability waves  

NASA Astrophysics Data System (ADS)

A brief survey is given on artificial excitation of instability waves in parallel flows. There are basically two categories of unstable flows: (1) convectively unstable and (2) absolutely unstable flows. The perturbation level in convectively unstable flows, e.g., boundary layers and most free shear flows, depends on the excitation only. On the other hand, absolutely unstable flows, e.g., wake flows and hot jets, do maintain fluctuations independent of an exterior excitation. Finally, effects of non-parallel mean flow and of varying boundary conditons on instability wave excitation are discussed.

Bechert, D. W.

1985-12-01

162

The Fall and the Rise of X-Rays from Dwarf Novae in Outburst: RXTE Observations of VW Hydri and WW Ceti  

NASA Technical Reports Server (NTRS)

In a dwarf nova, the accretion disk around the white dwarf is a source of ultraviolet, optical, and infrared photons, but is never hot enough to emit X-rays. Observed X-rays instead originate from the boundary layer between the disk and the white dwarf. As the disk switches between quiescence and outburst states, the 2-10 keV X-ray flux is usually seen to be anti-correlated with the optical brightness. Here we present RXTE monitoring observations of two dwarf novae, VW Hyi and WW Cet, confirming the optical/X-ray anti-correlation in these two systems. However, we do not detect any episodes of increased hard X-ray flux on the rise (out of two possible chances for WW Cet) or the decline (two for WW Cet and one for VW Hyi) from outburst, attributes that are clearly established in SS Cyg. The addition of these data to the existing literature establishes the fact that the behavior of SS Cyg is the exception, rather than the archetype as is often assumed. We speculate that only dwarf novae with a massive white dwarf may show these hard X-ray spikes.

Fertig, D.; Mukai, K.; Nelson, T.; Cannizzo, J. K.

2011-01-01

163

Simultaneous Observations of PKS 2155--304 with H.E.S.S., Fermi, RXTE and ATOM: Spectral Energy Distributions and Variability in a Low State  

SciTech Connect

We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155-304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and 2008 September 6 (MJD 54704-54715), jointly with the Fermi Gamma-ray Space Telescope and the HESS atmospheric Cherenkov array, providing the first simultaneous MeV-TeV spectral energy distribution (SED) with the new generation of {gamma}-ray telescopes. The ATOM telescope and the RXTE and Swift observatories provided optical and X-ray coverage of the low-energy component over the same time period. The object was close to the lowest archival X-ray and very high energy (VHE; >100 GeV) state, whereas the optical flux was much higher. The light curves show relatively little ({approx}30%) variability overall when compared to past flaring episodes, but we find a clear optical/VHE correlation and evidence for a correlation of the X-rays with the high-energy spectral index. Contrary to previous observations in the flaring state, we do not find any correlation between the X-ray and VHE components. Although synchrotron self-Compton models are often invoked to explain the SEDs of BL Lac objects, the most common versions of these models are at odds with the correlated variability we find in the various bands for PKS 2155-304.

Aharonian, F.; /Heidelberg, Max Planck Inst. /Dublin Inst.; Akhperjanian, A.G.; /Yerevan Phys. Inst.; Anton, G.; /Erlangen - Nuremberg U.; Barres de Almeida, U.; /Durham U.; Bazer-Bachi, A.R.; /Toulouse, CESR; Becherini, Y.; /APC, Paris; Behera, B.; /Heidelberg Observ.; Bernlohr, K.; /Heidelberg, Max Planck Inst. /Humboldt U., Berlin; Boisson, C.; /LUTH, Meudon; Bochow, A.; /Heidelberg, Max Planck Inst.; Borrel, V.; /Toulouse, CESR; Brion, E.; /DAPNIA, Saclay; Brucker, J.; /Erlangen - Nuremberg U.; Brun, P.; /DAPNIA, Saclay; Buhler, R.; /Heidelberg, Max Planck Inst.; Bulik, T.; /Warsaw, Copernicus Astron. Ctr.; Busching, I.; /Western Ontario U.; Boutelier, T.; /Grenoble Observ.; Chadwick, P.M.; /Durham U.; Charbonnier, A.; /Paris U., VI-VII; Chaves, R.C.G.; /Heidelberg, Max Planck Inst. /Durham U. /Ecole Polytechnique /Heidelberg, Max Planck Inst. /Annecy, LAPP /Humboldt U., Berlin /Durham U. /Namibia U. /Western Ontario U. /Ecole Polytechnique /Heidelberg, Max Planck Inst. /Durham U. /APC, Paris /Heidelberg, Max Planck Inst. /Dublin Inst. /Annecy, LAPP /Grenoble Observ. /Warsaw, Copernicus Astron. Ctr. /Cracow, INP /Heidelberg, Max Planck Inst. /Heidelberg Observ. /APC, Paris /Montpellier U. /Montpellier U. /Montpellier U. /Heidelberg, Max Planck Inst. /Ecole Polytechnique /Humboldt U., Berlin /Dublin Inst. /Montpellier U. /APC, Paris /SLAC; /more authors..

2009-05-07

164

J.T. Roberts' Science Fair  

NSDL National Science Digital Library

The following websites will be useful when preparing your science fair project. It is that time of year again! It is time to start planning your science fair project. All 7th and 8th grade students are required to participate in in the science fair. This is an opportunity to explore the exciting world in which we live. REQUIREMENTS: - Students will work ...

Greeley, Ms.

2007-11-03

165

Engaging Students in Nuclear Physics Science Camp  

Microsoft Academic Search

Getting students interested in the sciences is a difficult task that all teachers face. Hope College Summer Science Camps aim to do just this by providing interesting topics to engage students of all ages with the hope that they become excited about science and school in general. In order to enthuse high school students about Physics as a possible career

Sarah Prill

2012-01-01

166

8. POWERHOUSE INTERIOR SHOWING EXCITER No. 1 IN FOREGROUND, EXCITER ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. POWERHOUSE INTERIOR SHOWING EXCITER No. 1 IN FOREGROUND, EXCITER No. 2., AND GENERATOR UNITS BEHIND EXCITER No. 2 IN BACKGROUND. EXCITER No. 1 GENERATOR HAS A COVER OVER TOP HALF OF COMMUTATOR ELEMENT. VIEW TO NORTHWEST. - Rush Creek Hydroelectric System, Powerhouse Exciters, Rush Creek, June Lake, Mono County, CA

167

A Science Information Infrastructure  

NASA Astrophysics Data System (ADS)

We have created a partnership of science museums, research institutions, teachers, and other centers of informal science education to enable access to the rich resources of remote sensing data available from NASA and other sources and to deliver this information to the general community. We are creating science resource centers in the nation's science museums and planetarium facilities, linking them together through a national Science Information Infrastructure (SII). The SII framework is being founded on Internet connections between the resource centers, which are in turn linked to research institutions. The most up-to-date and exciting science data, related information, and interpretive material will be available from the research institutions. The science museums will present this information in appropriate ways that respond to the needs and interest of the general public and K--12 communities. The science information will be available through the World Wide Web using a Mosaic interface that individuals will use to explore the on-line materials through self-guided learning modules. K--12 teachers will have access to the materials and, in a workshop forum, learn to find and use the information to create lesson plans and curricula for their classrooms. Eventually, as the connectivity of schools and libraries improves, students and teachers will have access to the resource centers from their own locations. The core partnership of the SII includes the Center for EUV Astrophysics (CEA), and Smithsonian Astrophysical Observatory, Exploratorium, Lawrence Hall of Science, Smithsonian National Air and Space Museum, Science Museum of Virginia, New York Hall of Science, Adler Museum of Chicago, University of California Museum of Paleontology, Boston Museum of Science, and the Earth Observing Satellite Company (EOSAT). A demonstration of the application of resource center materials in the K--12 community is being conducted through the Science On-Line project at the Center for EUV Astrophysics. This work has been supported by a NASA Astrophysics Division grant and NASA contract NAS5-29298.

Christian, C. A.; Hawkins, I.; Malina, R. F.; Dow, K.; Murray, S.

1994-12-01

168

Safer Science: Building Safety Into Construction or Renovations  

NSDL National Science Digital Library

Designing a new science laboratory or renovating an existing one can be an exciting experience. Though science teachers may have a better understanding of laboratory needs than most administrators, many schools tend to limit or exclude them from the plann

Roy, Ken

2010-12-01

169

Goddard's Astrophysics Science Division Annual Report 2011  

NASA Technical Reports Server (NTRS)

The Astrophysics Science Division(ASD) at Goddard Space Flight Center(GSFC)is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radiowavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contract imaging techniques to serch for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, and provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and suppport the astronomical community, and enable future missions by conceiving new conepts and inventing new technologies.

Centrella, Joan; Reddy, Francis; Tyler, Pat

2012-01-01

170

Magnetostrictive resonance excitation.  

National Technical Information Service (NTIS)

The resonance frequency spectrum of a magnetostrictive sample is remotely determined by exciting the magnetostrictive property with an oscillating magnetic field. The permeability of a magnetostrictive material and concomitant coupling with a detection co...

R. B. Schwartz V. T. Kuokkala

1990-01-01

171

Multi-photon excitation microscopy  

PubMed Central

Multi-photon excitation (MPE) microscopy plays a growing role among microscopical techniques utilized for studying biological matter. In conjunction with confocal microscopy it can be considered the imaging workhorse of life science laboratories. Its roots can be found in a fundamental work written by Maria Goeppert Mayer more than 70 years ago. Nowadays, 2PE and MPE microscopes are expected to increase their impact in areas such biotechnology, neurobiology, embryology, tissue engineering, materials science where imaging can be coupled to the possibility of using the microscopes in an active way, too. As well, 2PE implementations in noninvasive optical bioscopy or laser-based treatments point out to the relevance in clinical applications. Here we report about some basic aspects related to the phenomenon, implications in three-dimensional imaging microscopy, practical aspects related to design and realization of MPE microscopes, and we only give a list of potential applications and variations on the theme in order to offer a starting point for advancing new applications and developments.

Diaspro, Alberto; Bianchini, Paolo; Vicidomini, Giuseppe; Faretta, Mario; Ramoino, Paola; Usai, Cesare

2006-01-01

172

'pseudo' Phase resolved spectroscopy of "Hear-beat" oscillations in IGR J17091-3624 with simultaneous XMM-Newton and RXTE observations  

NASA Astrophysics Data System (ADS)

IGR J17091-3624 is an X-ray transient discovered by INTEGRAL in April 2003 and is believed to be a galactic black hole candidate. It came into prominence during its recent outburst in February 2011 due to peculiar 'heart-beat' type variability patterns exhibited by the source in which the quasi-periodic mini-outbursts are repeated over time scale as short as 5 seconds. So far such variability pattern is observed only in GRS1915+105, which is famous for displaying variety of short term variability patterns. However, GRS1915+105 is considered to be an isolated exhibiting extreme variability whereas all other sources exhibit much gentler variability and over much longer time scale. Thus observation of 'heart-beat' type of short term variability in IGR J17091-3624 promotes it as missing-link between GRS1915+105 and rest of black-hole binaries. However, the possibility of in-depth study of the origin of such variability is hampered by complete lack of knowledge about the distance, black hole mass as well as inclination angle. Here we present the results of 'pseudo' phase resolved spectroscopy of simultaneous XMM-Newton and RXTE observations, which can constrain at least some of the unknown geometric parameters. This work demonstrates the importance of wide band X-ray spectroscopy of by simultaneous observations with focusing X-ray telescope and large area collimated detectors. Normally such simultaneous observations with different observatories are very difficult to realize due to variety of constraints, but with Astrosat these will be available by default and hence Astrosat will be ideally suitable for wide band X-ray spectroscopy of Galactic X-ray sources.

Vadawale, Santosh; Rao, Anjali

2012-07-01

173

LONG-TERM MULTI-WAVELENGTH STUDIES OF GRS 1915+105. I. A HIGH-ENERGY AND MID-INFRARED FOCUS WITH RXTE/INTEGRAL AND SPITZER  

SciTech Connect

To date, mid-infrared properties of Galactic black hole binaries have barely been investigated in the framework of multi-wavelength campaigns. Yet, studies in this spectral domain are crucial to get complementary information on the presence of dust and/or on the physical processes such as dust heating and thermal bremsstrahlung. Here, we report a long-term multi-wavelength study of the microquasar GRS 1915+105. On the one hand, we aimed at understanding the origins of the mid-infrared emission, and on the other hand, at searching for correlation with the high-energy and/or radio activities. We observed the source at several epochs between 2004 and 2006 with the photometer IRAC and spectrometer IRS, both mounted on the Spitzer Space Telescope. When available, we completed our set of data with quasi-simultaneous RXTE/INTEGRAL high-energy and/or Ryle radio observations from public archives. We then studied the mid-infrared environment and activities of GRS 1915+105 through spectral analysis and broadband fitting of its radio to X-ray spectral energy distributions. We detected polycyclic aromatic hydrocarbon molecules in all but one IRS spectra of GRS 1915+105 which unambiguously proves the presence of a dust component, likely photoionized by the high-energy emission. We also argue that this dust is distributed in a disk-like structure heated by the companion star, as observed in some Herbig Ae/Be and isolated cool giant stars. Moreover, we show that some of the soft X-ray emission emanating from the inner regions of the accretion disk is reprocessed and thermalized in the outer part. This leads to a mid-infrared excess that is very likely correlated to the soft X-ray emission. We exclude thermal bremsstrahlung as contributing significantly in this spectral domain.

Rahoui, F.; Chaty, S.; Rodriguez, J.; Fuchs, Y.; Mirabel, I. F. [Laboratoire AIM, CEA/DSM - CNRS - Universite Paris Diderot, Irfu/Service d'Astrophysique, Bat. 709, CEA/Saclay, F-91191 Gif-sur-Yvette (France); Pooley, G. G., E-mail: frahoui@cfa.harvard.ed [Astrophysics, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2010-06-01

174

Cross-calibration of the X-ray instruments onboard the Chandra, INTEGRAL, RXTE, Suzaku, Swift, and XMM-Newton observatories using G21.5-0.9  

NASA Astrophysics Data System (ADS)

Context. For many years, X-ray astronomy missions have used the Crab nebula as a celestial calibration source for the X-ray flux and spectral shape. However, the object is often too bright for current and future missions equipped with instruments with improved sensitivity. Aims: We use G21.5-0.9, a pulsar-wind nebula with a time-constant power-law spectrum and a flux of a few milli-Crab in the X-ray band, as a viable, fainter substitute to the Crab. Using this source, we conduct a cross-calibration study of the instruments onboard currently active observatories: Chandra ACIS, Suzaku XIS, Swift XRT, and XMM-Newton EPIC (MOS and pn) for the soft-band, and INTEGRAL IBIS-ISGRI, RXTE PCA, and Suzaku HXD-PIN for the hard band. Methods: We extract spectra from all instruments and fit under the same astrophysical assumptions. We compare the spectral parameters of the G21.5-0.9 model: power-law photon index, H-equivalent column density of the interstellar photoelectric absorption, and flux in the soft (2-8 keV) or hard (15-50 keV) energy band. Results: We identify systematic differences in the best-fit parameter values unattributable to statistical scatter of the data alone. We interpret these differences as due to residual cross-calibration problems. The differences can be as large as 20% and 9% for the soft-band flux and power-law index, respectively, and 46% for the hard-band flux. The results are plotted and tabulated as a useful reference for future calibration and scientific studies using multiple missions. This work is based on the activity of the International Astronomical Consortium for High Energy Calibration (IACHEC).

Tsujimoto, M.; Guainazzi, M.; Plucinsky, P. P.; Beardmore, A. P.; Ishida, M.; Natalucci, L.; Posson-Brown, J. L. L.; Read, A. M.; Saxton, R. D.; Shaposhnikov, N. V.

2011-01-01

175

Space Plasma Science as a Motivator for Education & Outreach  

Microsoft Academic Search

Education and public outreach (EPO) continue to play an important role in how science is funded by the federal government. The plasma science community has a responsibility to share their exciting science with the American public. Bruce Alberts, president of the National Academy of Sciences, and Neal Lane, former head of NSF, are on record as strong advocates of scientists

Paul Dusenbery

1999-01-01

176

Outer Space Place: Exploring Space at the Maryland Science Center  

Microsoft Academic Search

The Maryland Science Center has been the state's premier vehicle for informal science education for over 20 years. Every day thousands of school children, families, and out-of-state visitors come for fun and come away with ideas, exciting experiences, and an appetite for more information about science. Opened on April 15, 1999, Outer Space Place (OSP) consolidates the Science Center's space

M. W. Jan; F. Mendez

1999-01-01

177

Science and Politics in the Philosophy of Science of Popper, Polanyi, and Kuhn  

Microsoft Academic Search

The names of Karl Popper, Michael Polanyi, and Thomas Kuhn are well-known among scientists and among historians and philosophers of science. Around 1960 they published books that excited considerable discussion because of their independent rejection of the philosophical tradition that uses simple empiricism or positivism to differentiate science from religion, metaphysics, ideology, or pseudo-science. Popper's original field of expertise was

Mary Jo Nye

2006-01-01

178

High-Dispersion Spectroscopy of the X-Ray Transient RXTE J0421+560 (=CI Camelopardalis) during Outburst  

NASA Astrophysics Data System (ADS)

We obtained high-dispersion spectroscopy of CI Cam, the optical counterpart of XTE J0421+560, 2 weeks after the peak of its short outburst in 1998 April. The optical counterpart is a supergiant B[e] star that is emitting a two-component wind, a cool, low-velocity wind and a hot, high-velocity wind. The cool wind, which is the source of narrow emission lines of neutral and ionized metals, has a velocity of 32 km s-1 and a temperature near 8000 K. It is dense, roughly spherical, fills the space around the sgB[e] star, and, based on the size of an infrared-emitting dust shell around the system, extends to a radius between 13 and 50 AU. It carries away mass at a high rate, M>10-6Msolaryr-1. The hot wind has a velocity in excess of 2500 km s-1 and a temperature of 1.7+/-0.3×104 K. From an ultraviolet spectrogram of CI Cam obtained in 2000 March with Hubble Space Telescope, we derive a differential extinction E(B-V)=0.85+/-0.05. We show that the distance to CI Cam is greater than 5 kpc. Based on this revised distance, the X-ray luminosity at the peak of the outburst was L(2-25 keV)>3.0×1038 ergs s-1, making CI Cam one of the most luminous X-ray transients. The ratio of quiescent luminosity to peak luminosity in the 2-25 keV band is Lq/Lp<1.7×10-6. The compact star in CI Cam is immersed in the dense circumstellar wind from the sgB[e] star and burrows through the wind, producing little X-ray emission except for rare transient outbursts. This picture, a compact star traveling in a wide orbit through the dense circumstellar envelope of a sgB[e] star, occasionally producing transient X-ray outbursts, makes CI Cam unique among the known X-ray binaries. There is strong circumstantial evidence that the compact object is a black hole, not a neutron star. We speculate that the X-ray outburst was short because the accretion disk around the compact star is fed from a stellar wind and is smaller than disks fed by Roche lobe overflow. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Robinson, Edward L.; Ivans, Inese I.; Welsh, William F.

2002-02-01

179

True Tales of Science  

NSDL National Science Digital Library

There's no better way to understand the work of a scientist than to have it explained in the scientist's own words. Scientific journals, personal accounts of research projects, and documentaries can give students an authentic view of the scientific process. It's an important step towards getting students excited about science and the work of scientists, while countering any misconceptions or stereotypes that may have already developed. This article suggests books and activities for teaching the processes of science to elementary readers. Tips for choosing appropriate books are also included.

Melber, Leah M.

2003-10-01

180

Try Science  

NSDL National Science Digital Library

TryScience contains games and virtual reality adventures, virtual field trips to museums and science centers, and experiments. There is a Starfleet Academy virtual reality game involving communications, engineering, environments, and lifeforms; an electrolysis experiment that can be conducted online or at home; and a game about an African Naked Mole-rat colony. Experiments are categorized by: Earth science, biological science, mathematics, physical science, space science, technology and engineering, chemistry, social science, and medicine and health.

181

Temperature and excitable cells  

PubMed Central

Temperature affects a host of biological processes, one of which is the conduction velocity of action potentials (AP). The velocity-temperature profile of APs has remained remarkably conserved across excitable animal and plant cells. Herein, we will not analyze this behavior in terms of temperature sensitivities of single molecules (e.g., ion channels), but rather we present a phenomenological thermodynamic interpretation. By assuming that APs are acoustic phenomena, one arrives at testable predictions about the temperature-dependence of the macroscopic material properties of the excitable cell membrane. These material properties set constraints on the excitability of a cell membrane and allow us to hypothesize about its typical relaxation timescales. The presented approach—by virtue of its thermodynamic nature—is by no means limited to temperature. It applies equally well to all thermodynamic variables (e.g., mechanical stretch, pH, ion concentrations, etc.) and to underline this argument we discuss some implications and predictions for sensory physiology.

Fillafer, Christian; Schneider, Matthias F

2013-01-01

182

Science Sampler : Reading science  

NSDL National Science Digital Library

Nonfiction books have the power to excite students about learning and fuel their desire to know more about a topic or person. Using a variety of books can differentiate instruction and provide suitable reading to students at all levels and for almost any interest. This article provides a list of recommended reading and some lesson ideas that correspond with the material.

Carlson, Kenneth

2005-01-01

183

Excitation Methods for Bridge Structures  

SciTech Connect

This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.

Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.

1999-02-08

184

Science history  

Microsoft Academic Search

A science history content in a science course is a humanizing element which makes the science appeal more strongly to imaginative and creative minds. It also provides perspective and prepares the pupil for the ever-changing character of modern science. Examples are given of charts which can key science history to its social and political background and which illustrate the interdependence

A J Woodall

1967-01-01

185

Highly Excited Atoms.  

National Technical Information Service (NTIS)

The major accomplishment under this contract was the innovation of techniques for the production and detection of highly excited atoms (Rydberg atoms), and a series of studies on the properties of Rydberg atoms in strong electric fields. Partly as a resul...

D. Kleppner

1977-01-01

186

Computer Science  

NSDL National Science Digital Library

Computer science is the study of computational systems and their use in representing important problems in science and society. Major topics include computational science, software systems, network systems, theory of computation, machine learning, and human-computer interaction.

K-12 Outreach,

187

Authentic science and school science  

Microsoft Academic Search

Current concerns about inappropriate views that students have about science and suggested remedies such as more philosophy of science courses for science teachers are similar to those advanced during the 1960s curriculum reform movement. However, evidence from the ‘60s and the ‘80s is that additional courses in the philosophy of science have little effect on science teachers’ classroom behaviour or

P. James Gaskell

1992-01-01

188

NASA Science Served Family Style  

NASA Astrophysics Data System (ADS)

Family oriented innovative programs extend the reach of many traditional out-of-school venues to involve the entire family in learning in comfortable and fun environments. Research shows that parental involvement is key to increasing student achievement outcomes, and family-oriented programs have a direct impact on student performance. Because families have the greatest influence on children's attitudes towards education and career choices, we have developed a Family Science program that provides families a venue where they can explore the importance of science and technology in our daily lives by engaging in learning activities that change their perception and understanding of science. NASA Family Science Night strives to change the way that students and their families participate in science, within the program and beyond. After three years of pilot implementation and assessment, our evaluation data shows that Family Science Night participants have positive change in their attitudes and involvement in science.  Even after a single session, families are more likely to engage in external science-related activities and are increasingly excited about science in their everyday lives.  As we enter our dissemination phase, NASA Family Science Night will be compiling and releasing initial evaluation results, and providing facilitator training and online support resources. Support for NASA Family Science Nights is provided in part through NASA ROSES grant NNH06ZDA001N.

Noel-Storr, Jacob; Mitchell, S.; Drobnes, E.

2010-01-01

189

Excitation and Characterization of Chladni Plate Patterns  

NASA Astrophysics Data System (ADS)

When a thin metal plate with a small amount of sand on it is made to vibrate, aesthetically pleasing sand patterns can form along the nodal lines of the plate. These symmetric patterns are called Chladni Patterns. Students taking PHY 101 Physical Science in the Arts at Eastern Michigan University create these patterns by pulling a violin bow across the edge of a plate, or by using a mechanical oscillator to drive the center of a plate. These two methods only allow a small subset of all possible points on the plate to be excited. We designed and built an electronic device that allows its user to excite the plate at any point. We present patterns created with this electronic device and other methods, and describe ways to model the observed patterns.

Bourke, Shannon; Behringer, Ernest

2011-04-01

190

Communicating Science  

NASA Astrophysics Data System (ADS)

Introduction: what this book is about and why you might want to read it; Prologue: three orphans share a common paternity: professional science communication, popular journalism, and literary fiction are not as separate as they seem; Part I. Professional Science Communication: 1. Spreading the word: the endless struggle to publish professional science; 2. Walk like an Egyptian: the alien feeling of professional science writing; 3. The future's bright? Professional science communication in the age of the internet; 4. Counting the horse's teeth: professional standards in science's barter economy; 5. Separating the wheat from the chaff: peer review on trial; Part II. Science for the Public: What Science Do People Need and How Might They Get It?: 6. The Public Understanding of Science (PUS) movement and its problems; 7. Public engagement with science and technology (PEST): fine principle, difficult practice; 8. Citizen scientists? Democratic input into science policy; 9. Teaching and learning science in schools: implications for popular science communication; Part III. Popular Science Communication: The Press and Broadcasting: 10. What every scientist should know about mass media; 11. What every scientist should know about journalists; 12. The influence of new media; 13. How the media represents science; 14. How should science journalists behave?; Part IV. The Origins of Science in Cultural Context: Five Historic Dramas: 15. A terrible storm in Wittenberg: natural knowledge through sorcery and evil; 16. A terrible storm in the Mediterranean: controlling nature with white magic and religion; 17. Thieving magpies: the subtle art of false projecting; 18. Foolish virtuosi: natural philosophy emerges as a distinct discipline but many cannot take it seriously; 19. Is scientific knowledge 'true' or should it just be 'truthfully' deployed?; Part V. Science in Literature: 20. Science and the Gothic: the three big nineteenth-century monster stories; 21. Science fiction: serious literature of ideas or low-grade entertainment?; 22. Science in British literary fiction; 23. Science on stage: the politics and ethics of science in cultural and educational contexts.

Russell, Nicholas

2009-10-01

191

Reverse Your Science Fair with Educational Partnerships  

ERIC Educational Resources Information Center

This article suggests several ways teachers can get their students really excited about science by bringing scientists to the science fair in a different role than the traditional "judge." With a bit more effort, scientists can become actively involved as presenters of hands-on activities. This article discusses: what happens when the tables are…

Rose, Jordan; Zardetto-Smith, Andrea; Mu, Keli; Demetrikopoulos, Melissa K.

2004-01-01

192

Excited-State Dynamics in Folic Acid and 6-CARBOXYPTERIN upon Uva Excitation  

NASA Astrophysics Data System (ADS)

The excited-state dynamics of folic acid (FA) and 6-carboxypterin (6CP) are poorly understood and work is needed to uncover the relaxation pathways that ultimately lead to their oxidative damage of DNA. In our approach, broad-band transient absorption spectroscopy was used to monitor the evolution of the excited states in FA and 6CP in basic aqueous solution upon excitation at 350 nm. In addition, quantum-chemical calculations were performed to assist in the interpretation of the experimental results and in the postulation of kinetic mechanisms. The combined experimental and computational results support a kinetic model where excitation of FA results in ultrafast charge separation (? = 0.6 ps), which decays back to the ground state primarily by charge recombination with a lifetime of 2.2 ps. A small fraction of the charge transfer state undergoes intersystem crossing to populate the lowest-energy triplet state with a lifetime of 200 ps. On the other hand, a large fraction of the initially excited singlet state in 6CP decays by fluorescence emission with a lifetime of 100 ps, while intersystem crossing to the triplet state occurs with a lifetime of 4.4 ns. The potential implications of these results to the oxidative damage of DNA by FA and 6CP will be discussed. Funding from the National Science Foundation is gratefully acknowledged (CHE-1255084).

Huang, Huijuan; Vogt, R. Aaron; Crespo-Hernandez, Carlos E.

2013-06-01

193

Soapy Science. Teaching Science.  

ERIC Educational Resources Information Center

Describes a science and math activity that involves bubbles, shapes, colors, and solid geometry. Students build geometric shapes with soda straws and submerge the shapes in soapy water, allowing them to review basic geometry concepts, test hypotheses, and learn about other concepts such as diffraction, interference colors, and evaporation. (TJQ)

Leyden, Michael

1997-01-01

194

Magnetostrictive resonance excitation  

DOEpatents

The resonance frequency spectrum of a magnetostrictive sample is remotely determined by exciting the magnetostrictive property with an oscillating magnetic field. The permeability of a magnetostrictive material and concomitant coupling with a detection coil varies with the strain in the material whereby resonance responses of the sample can be readily detected. A suitable sample may be a magnetostrictive material or some other material having at least one side coated with a magnetostrictive material. When the sample is a suitable shape, i.e., a cube, rectangular parallelepiped, solid sphere or spherical shell, the elastic moduli or the material can be analytically determined from the measured resonance frequency spectrum. No mechanical transducers are required and the sample excitation is obtained without contact with the sample, leading to highly reproducible results and a measurement capability over a wide temperature range, e.g. from liquid nitrogen temperature to the Curie temperature of the magnetostrictive material.

Schwarz, Ricardo B. (Los Alamos, NM) [Los Alamos, NM; Kuokkala, Veli-Tapani (Tampere, FI) [Tampere, FI

1992-01-01

195

Magnetostrictive resonance excitation  

US Patent & Trademark Office Database

The resonance frequency spectrum of a magnetostrictive sample is remotely determined by exciting the magnetostrictive property with an oscillating magnetic field. The permeability of a magnetostrictive material and concomitant coupling with a detection coil varies with the strain in the material whereby resonance responses of the sample can be readily detected. A suitable sample may be a magnetostrictive material or some other material having at least one side coated with a magnetostrictive material. When the sample is a suitable shape, i.e., a cube, rectangular parallelepiped, solid sphere or spherical shell, the elastic moduli or the material can be analytically determined from the measured resonance frequency spectrum. No mechanical transducers are required and the sample excitation is obtained without contact with the sample, leading to highly reproducible results and a measurement capability over a wide temperature range, e.g. from liquid nitrogen temperature to the Curie temperature of the magnetostrictive material.

1992-09-29

196

Aperture excited dielectric antennas  

NASA Technical Reports Server (NTRS)

The results of a comprehensive experimental and theoretical study of the effect of placing dielectric objects over the aperture of waveguide antennas are presented. Experimental measurements of the radiation patterns, gain, impedance, near-field amplitude, and pattern and impedance coupling between pairs of antennas are given for various Plexiglas shapes, including the sphere and the cube, excited by rectangular, circular, and square waveguide feed apertures. The waveguide excitation of a dielectric sphere is modeled using the Huygens' source, and expressions for the resulting electric fields, directivity, and efficiency are derived. Calculations using this model show good overall agreement with experimental patterns and directivity measurements. The waveguide under an infinite dielectric slab is used as an impedance model. Calculations using this model agree qualitatively with the measured impedance data. It is concluded that dielectric loaded antennas such as the waveguide excited sphere, cube, or sphere-cylinder can produce directivities in excess of that obtained by a uniformly illuminated aperture of the same cross section, particularly for dielectric objects with dimensions of 2 wavelengths or less. It is also shown that for certain configurations coupling between two antennas of this type is less than that for the same antennas without dielectric loading.

Crosswell, W. F.; Chatterjee, J. S.; Mason, V. B.; Tai, C. T.

1974-01-01

197

Nonlinear excitations in lattices  

NASA Astrophysics Data System (ADS)

We analyze some of the properties of nonlinear excitations occurring in lattices such as polarons, bipolarons or discrete breathers (DBs). While polarons and bipolarons are the result of the self-trapping of one or two electronic carriers by the lattice distortion they generate, DBs occur in networks of identical non-harmonic oscillators as exact solutions to the equations of motion that are both time-periodic and spatially localized. In certain limits, these excitations may be described by a common class of models: the Discrete Nonlinear Schrodinger Equation and its generalizations. We first use an exact perturbative expansion to derive the bipolaronic phase diagram of the 1D adiabatic Holstein-Hubbard model (HH) in the strong coupling limit. In the second part of the thesis we study DBs on d-dimensional cubic lattices with arbitrary power nonlinearity. We compare the exact results to an exponential ansatz approach and to the solution to the Single Nonlinear Impurity (SNI) model. We show that DB excitation thresholds can be evaluated explicitly in the limit of high nonlinearity, and we prove a conjecture by Bustamante and Molina [PRB 62, 15287 (2000)] that the limiting value of the SNI bound state energy is universal as the nonlinearity tends to infinity.

Zhou, Jun

198

Harmonically excited orbital variations  

SciTech Connect

Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs.

Morgan, T.

1985-08-06

199

Apparatus for photon excited catalysis  

NASA Technical Reports Server (NTRS)

An apparatus is described for increasing the yield of photonically excited gas phase reactions by extracting excess energy from unstable, excited species by contacting the species with the surface of a finely divided solid.

Saffren, M. M. (inventor)

1977-01-01

200

Science Buddies.  

ERIC Educational Resources Information Center

Describes the science buddies program that pairs a 7th grade life science class with a 2nd or 3rd grade class in a yearlong partnership of science adventures. Includes sample activities and National Science Education Standards related to the activities. (Author/KHR)

Potenza, Susan Ade

2003-01-01

201

Practicing Science: The Investigative Approach in College Science Teaching  

NSDL National Science Digital Library

In this collection of ten articles reprinted from the Journal of College Science Teaching, college and university science professors show how they have used investigative learning--or inquiry-based instruction--to introduce students to the process of science. These first-person accounts demonstrate how students, including non-science majors, can learn to do science as it is done in the real world--through hypothesis building, observation, and experimental design. The higher education faculty represented in this book is committed to the investigative approach. As one contributor writes, "Would I return to lecturing in a traditional fashion? Not a chance. The excitement and energy of a room of students working in groups, challenging each other, and questioning each other is what I'll always want to see in my classroom."

Press, Nsta

2001-01-01

202

Biopolitical science.  

PubMed

This article develops a theoretical framework for biopolitical science as a science of political animals. This science moves through three levels of deep political history: the universal political history of the species, the cultural political history of the group, and the individual political history of animals in the group. To illustrate the particular application of biopolitical science, this essay shows how this science would help us to understand Abraham Lincoln's Emancipation Proclamation of January 1, 1863. PMID:20812796

Arnhart, Larry

2010-03-01

203

Follow-Up with Students after 6 Years of Participation in Project Excite  

ERIC Educational Resources Information Center

Project EXCITE is a program for minority students that supplements the regular school offerings with an emphasis on enhancing students' interest and performance in math and science. This study examines the experience and perceptions of 14 student participants in the program and their parents. In student and parent interviews, Project EXCITE was…

Lee, Seon-Young; Olszewski-Kubilius, Paula; Peternel, George

2009-01-01

204

FOREWORD Nanomaterials science Nanomaterials science  

NASA Astrophysics Data System (ADS)

The nanometer regime covers the transition from condensed matter behavior to atomic and molecular properties and thus is a very rich but also very demanding area in materials science. Close to the condensed matter side, properties and functions might still very well be scalable, whereas close to the atomic and molecular side, the scalability is mostly lost. Properties and functions change qualitatively or quantitatively by orders of magnitude when the dimensions become smaller than a critical size in the nanometer range. Examples are the ballistic regime for electron or spin transport at dimensions below the mean free path, near-field effects in scanning near-field optical microscopy and quantum wells when the dimensions are below an appropriate wavelength, novel electronic, mechanical, and chemical properties when the number of bulk atoms becomes smaller than that of surface atoms, quantum conduction, and Coulomb blockade. Thus, by going below a certain size, an abundance of novel properties and functions are at one's disposal, or, in other words, we can functionalize materials simply by reducing their size to the nanoscale. The key to the future lies in the functions that we give to materials, not just in finding 'novel functional materials'. This catch expression in many materials science programs and initiatives of the past two decades sounds great, but it is not what really counts. All materials are functional in one way or another and, therefore, all new materials are 'novel functional materials'. Certainly, finding new materials is always an important part of progress, but we should also focus on the much larger domain of novel functions that we can give to existing or modified materials. A good example is semiconductors: they are fifty or more years old and their properties are very well known, but they were not of widespread interest and use until the transistor changed their destiny into being the central material in the information technology revolution. Interfaces gave them their functions, and shaping them into ever-smaller functional components made them indispensably omnipresent as transistors—produced in billions per person and per year—and they are no doubt the rulers of today's technical world. The semiconductor and transistor serve as an inspiring example of functionalizing materials. The developments of microelectronics profited very much from scalability, that is, the properties and functions do not change significantly with size. Therefore, every step toward smaller dimensions was a technical and commercial challenge with risks well under control. The transition to the nanoscale, however, is discontinuous. Examples of this transition are the local probe methods that exploit the mechanically controlled proximity to the object under consideration and that have become indispensable as microscopes and as measuring and modifying tools, the size of molecular components that are much smaller than the smallest possibly achievable transistor, the properties and functions of materials below a critical size as mentioned above, the continuum properties versus discrete ones, and novel concepts inspired by living nature. Those novel concepts include growing circuits first and building the active components at the nodes afterwards and measuring weak by weak, small by small, and many by many. It is these discontinuous steps that make the nanoscale different, not just smaller. They pose exciting challenges, open great opportunities and nearly unlimited possibilities, but they also carry serious technical, commercial, environmental, and health risks. The nanoscale is also a great opportunity for materials science in general. Materials science is interdisciplinary per se. A materials scientist should have a reasonable understanding of physics, chemistry, engineering, and more recently, also biology. Certainly one can always team up with representatives from other disciplines and forge collaborations. However, an effective team can only emerge from a common understanding of the respective languages and problems. Th

Rohrer, Heinrich

2010-10-01

205

No Compton Reflection In a Chandra/RXTE Observation of Mkn 509: Implications for the Fe-K Line Emission From Accreting X-Ray Sources  

NASA Technical Reports Server (NTRS)

We report the results of simultaneous Chandra and RXTE observations of the Seyfert 1 galaxy Mkn 509. We deconvolve the broad and narrow Fe-K emission-line components for which we measure rest-frame equivalent widths of 119+/-18 eV and 57+/-13 eV respectively. The broad line has a FWHM of 57,600((sup 14,400)(sub -21,000)) km/s and the narrow line is unresolved, with an upper limit on the FWHM of 4,940 km/s. Both components must originate in cool matter since we measure rest-frame center energies of 6.36((sup +0.13)(sub -0.12)) keV and 6.42+/-0.01 keV for the broad and narrow line respectively. This rules out He-like and H-like Fe for the origin of both the broad and narrow lines. If, as is widely accepted, the broad Fe-K line originates in Thomson-thick matter (such as an accretion disk), then one expects to observe spectral curvature above approximately 10 keV, (commensurate with the observed broad line), characteristic of the Compton-reflection continuum. However our data sets very stringent limits on deviations of the observed continuum from a power law. Light travel-time delays cannot be invoked to explain anomalies in the relative strengths of the broad Ferry line and Compton-reflection continuum since they are supposed to originate in the same physical location. We are forced to conclude that both the broad and narrow Fe-K lines had to originate in Thomson-thin matter during our observation. This result, for a single observation of just one source, means that our understanding of Fe K line emission and Compton reflection from accreting X-ray sources in general needs to be re-examined. For example, if an irradiated accretion disk existed in Mkn 509 at the time of the observations, the lack of spectral curvature above approximately 10 keV suggests two possibilities. Either the disk was Thomson-thick and highly ionized, having negligible Fe-K line emission and photoelectric absorption or the disk was Thomson-thin producing some or all of the broad Fe-K line emission. In the former case, the broad Fe-K line had to have produced in a Thomson-thin region elsewhere. In both cases the predicted spectral curvature above approximately 10 keV is negligible. An additional implication of our results is that any putative obscuring torus in the system, required by unification models of active galaxies, must also be Thomson-thin. The same applies to the optical broad line region (BLR) if it has a substantial covering factor.

Yaqoob, Tahir; Padmanabhan, Urmila; Kraemer, Steven B.; Crenshaw, D. Michael; Mckernan, Barry; George, Ian M.; Turner, T. Jane; White, Nicholas E. (Technical Monitor)

2002-01-01

206

Science Fiction and Science Education.  

ERIC Educational Resources Information Center

Uses science fiction films such as "Jurassic Park" or "Anaconda" to teach science concepts while fostering student interest. Advocates science fiction as a teaching tool to improve learning and motivation. Describes how to use science fiction in the classroom with the sample activity Twister. (YDS)

Cavanaugh, Terence

2002-01-01

207

Electronic excitations of adsorbed CO  

NASA Astrophysics Data System (ADS)

Electronic excitations of CO adsorbed on Ir(111) are probed by energy dependent angle-resolved electron energy loss spectroscopy. The results are related to other CO adsorption systems and to recent theoretical investigations. Triplet excitations as well as charge transfer excitations are identified in the 5-7 eV loss region. Intramolecular singlet excitations are most likely to be responsible for the loss features at 13-15 eV. Excitations involving the 5? orbital of chemisorbed CO are complex and distinctly different in character from their respective gas phase counterparts.

Netzer, F. P.; Mack, J. U.; Bertel, E.; Matthew, J. A. D.

1985-09-01

208

Electronic excitations of adsorbed CO  

NASA Astrophysics Data System (ADS)

Electronic excitations of CO adsorbed on Ir(111) are probed by energy dependent angle-resolved electron energy loss spectroscopy. The results are related to other CO adsorption systems and to recent theoretical investigations. Triplet excitations as well as charge transfer excitations are identified in the 5-7 eV loss region. Intramolecular singlet excitations are most likely to be responsible for the loss features at 13-15 eV. Excitations involving the 5? orbital of chemisorbed CO are complex and distinctly different in character from their respective gas phase counterparts.

Netzer, F. P.; Mack, J. U.; Bertel, E.; Matthew, J. A. D.

209

Excited States and Photons  

NSDL National Science Digital Library

Investigate how atoms can be excited to give off radiation (photons) with models of electron energy diagrams. Explore the effects of energy levels in atoms through interactive computer models. Learn about the different electron orbitals of an atom, and explore three-dimensional models of the atoms. Learn about photons and why they are emitted, and gain an understanding of the link between energy levels and photons as you discover how an atomÂs electron configuration affects which wavelengths of light it will admit or absorb.

Consortium, The C.

2011-12-13

210

Variability and Spectral Studies of Luminous Seyfert 1 Galaxy Fairall 9. Search for the Reflection Component is a Quasar: RXTE and ASCA Observation of a Nearby Radio-Quiet Quasar MR 2251-178  

NASA Technical Reports Server (NTRS)

Monitoring observations with interval of 3 days using RXTE (X Ray Timing Explorer) of the luminous Seyfert 1 galaxy Fairall 9 were performed for one year. The purpose of the observations were to study the variability of Fairall 9 and compare the results with those from the radio-loud object 3C 390.3. The data has been received and analysis is underway, using the new background model. An observation of the quasar MR 2251-178 was made in order to determine whether or not it has a reflection component. Older background models gave an unacceptable subtraction and analysis is underway using the new background model. The observation of NGC 6300 showed that the X-ray spectrum from this Seyfert 2 galaxy appears to be dominated by Compton reflection.

Leighly, Karen M.

1999-01-01

211

Magnetic Excitations in LaMnPO  

NASA Astrophysics Data System (ADS)

We performed inelastic neutron scattering experiments on LaMnPO at the BT-7 triple-axis spectrometer at NIST Center for Neutron Research. LaMnPO is an insulating pnictide compound and is antiferromagnetically ordered below TN = 375 K. Constant energy scans were performed above TN, and revealed spin-spin correlations in the paramagnetic state with characteristic wavevector Q = 1.6 å-1, near the antiferromagnetic ordering wavevector QAFM = 1.55 å-1. We performed constant wavevector scans above and below TN and these show there is a q-dependent and temperature-dependent energy gap in the magnetic excitations that vanishes at TN = 375 K. Constant energy scans below TN show the peak in the magnetic excitations does not change up to a measured energy transfer of 15 meV, suggesting exchange interactions are quite strong. The magnetic excitations in LaMnPO are similar to those observed in the parent compounds of the iron pnictide superconductors. Research supported by a National Security Science and Engineering Faculty Fellowship by the AFOSR

McNally, Daniel; Simonson, Jack; Smith, Greg; Lynn, Jeff; Zhao, Yang; Aronson, Meigan

2013-03-01

212

Excitability in Dictyostelium development  

NASA Astrophysics Data System (ADS)

Discovering how populations of cells reliably develop into complex multi-cellular structures is a key challenge in modern developmental biology. This requires an understanding of how networks at the single-cell level, when combined with intercellular signaling and environmental cues, give rise to the collective behaviors observed in cellular populations. I will present work in collaboration with the Gregor lab, showing that the signal-relay response of starved cells of the amoebae Dictyostelium discoideum can be well modeled as an excitable system. This is in contrast to existing models of the network that postulate a feed-forward cascade. I then extend the signal-relay model to describe how spatial gradient sensing may be achieved via excitability. One potential advantage of relying on feedback for gradient sensing is in preventing ``cheaters'' that do not produce signals from taking over the population. I then combine these models of single-cell signaling and chemotaxis to perform large-scale agent-based simulations of aggregating populations. This allows direct study of how variations in single-cell dynamics modify population behavior. In order to further test this model, I use the results of a screen for mutant cell lines that exhibit altered collective patterns. Finally, I use an existing FRET movie database of starved cell populations at varying cell densities and dilution rates to study heterogeneity in repeated spatio-temporal activity patterns.

Schwab, David

2013-03-01

213

Nuclear excited xenon flashlamp  

SciTech Connect

The optical emissions of nuclear excited Xenon plasmas were investigated to determine basic parameters important to photolytic pumping of lasers. Gas mixtures of Helium-3 and Xenon were irradiated in the steady state mode in the University of Florida Training Reactor at neutron flux levels of about 10/sup 12//cm/sup 2/.s, generating a power density in the gas of approximately 3 milliwatts/cm/sup 3/. Optical emissions from the gas were primarily due to Xe/sub 2/* band emission at 172 nm with a few Xell lines in the visible and ir. Energy transfer from the /sup 3/He(n,p)T reaction to the Xe/sub 2/* 172 nm band was 67.0% +- 10%. High pressure gas mixtures (4 atm.) of Helium-3 and Xenon were irradiated in the pulse mode (250 ..mu..s FWHM) at the fast burst reactor at the Aberdeen Pulsed Radiation Facility at thermal neutron flux levels of about 10/sup 17//cm/sup 2/.s, generating a power density in the gas of about 1 kilowatt/cm/sup 3/. Optical emissions from the gas extended from the vacuum ultraviolet through the visible to the infrared, resembling a discharge excited lamp with a current density of about 1500 amp./cm/sup 2/. Such a lamp could pump a Neodymium YAG or liquid laser.

Cox, J.D.

1982-01-01

214

Connecting Science and Literacy in the Classroom: Using Space and Earth Science to Support Language Arts  

NASA Astrophysics Data System (ADS)

The connections between science and literacy in the classroom have received increasing attention over the last two decades, as more and more evidence demonstrates that science provides an exciting vehicle in which to engage students on the path to literacy improvement. Combining literacy with science allows students to creatively explore the world or universe, and it. Combining science and literacy improves both reading and science scores, and increases students’ interest in science. At a time when over 40% of students beyond the 5th grade are reading two or more levels below grade level and are struggling with their current materials, finding ways to excite and engage them in the reading process is key. Literacy programs incorporating unique space science content can help prepare children for standardized language arts tests. It also engages our nation’s youngest learners and their teachers with the science, math, and technology of exploration in a language arts format. This session focuses on programs and products that bring the excitement of earth and space science into the literacy classroom, with a focus on research-based approached to combining science and language arts. Reading, Writing and Rings! Grades 1-2

Wessen, A. S.; Cobabe-Ammann, E. A.

2009-12-01

215

Science Poetry in Two Voices: Poetry and the Nature of Science  

ERIC Educational Resources Information Center

Poetry can be used during science instruction to foster interest, excitement, and wonder among elementary-level students. Children can read poetry, or have poetry read to them, as a way of learning about their world. They can also create poems to share their own science learning with others. We introduce two formats of the Poetry in Two Voices…

Frazier, Wendy M.; Murray, Kristen B.

2009-01-01

216

Try Science  

NSDL National Science Digital Library

Try Science is a website supported by IBM Corporation, the New York Hall of Science (NYHOS), the Association of Science-Technology Centers (ASTC), and science centers worldwide. The site provides a variety of mathematics, science and technology experiments and activities for students. Many of the activities are interactive, although the experiments are largely meant to be conducted offline. A section on Field Trips allows visitors to search for local science centers, which are described as "places where people of all ages can learn at their own pace, engage their curiosity, use their senses to ask and answer questions, and explain to others what they have learned." Webcams are set up to let visitors view activities at select science and technology centers worldwide. A section for teachers provides suggestions for how to use TryScience in the Classroom, discusses how the website meets Standards in the U.S, Australia and United Kingdom, offers some testimony from teachers who have used TryScience, and lists several professional development programs offered by science centers. Parents will also find a section with some helpful information about science and education along with resources on ways to get involved. Sending one of the Try Science experiments home with students is one suggested way that teachers can get parents involved in their kid's science education. Note that many of the pages require Flash plug-ins.

217

Science Alive!  

NSDL National Science Digital Library

An elementary school brings in community volunteers for a full-day, all-school event focused on real world science. This article describes the planning process and types of science professionals and non-professionals recruited for the event.

Tally-Foos, Kay

2005-01-01

218

Science Notes.  

ERIC Educational Resources Information Center

Presented are 29 science activities for secondary school science instruction. Topic areas include botany, genetics, biochemistry, anatomy, entomology, molecular structure, spreadsheets, chemistry, mechanics, astronomy, relativity, aeronautics, instrumentation, electrostatics, quantum mechanics, and laboratory interfacing. (CW)

School Science Review, 1990

1990-01-01

219

Science Notes.  

ERIC Educational Resources Information Center

Presented are 27 science activities for secondary school science instruction. Topic areas include microbiology, botany, biochemistry, genetics, safety, earthquakes, problem solving, electricity, heat, solutions, mechanics, quantum mechanics, flame tests, and molecular structure. (CW)

School Science Review, 1990

1990-01-01

220

Simple Science  

ERIC Educational Resources Information Center

This brief article presents some quick and easy science experiments for those dreary winter days when classrooms need a pick-me-up. These seemingly easy science experiments will make a lasting impact on students.

Cowens, John

2006-01-01

221

Dramatic Science  

NSDL National Science Digital Library

The setting: the science classroom. The characters: you and your students. The scene: Your students acting out scientific discoveries, modeling a frog's life cycle, mimicking the transition from liquid to solid. This is dramatic science , a teachi

Mcgregor, Debbie; Precious, Wendy

2010-10-01

222

Science Scope.  

ERIC Educational Resources Information Center

Discusses an education project launched by the National Academy of Sciences and the Pentagon to turn laid-off aerospace engineers into science teachers at Los Angeles middle schools and high schools. (MKR)

Stone, Richard, Ed.

1995-01-01

223

Forensic Science  

ERIC Educational Resources Information Center

A course is described, which was given during an interim, with an enrollment of 41 students. The course involved an in-depth study of forensic science, involving students with the methodology of science. (DF)

Berry, Keith O.; Nigh, W. G.

1973-01-01

224

Science Sleuths.  

ERIC Educational Resources Information Center

Describes a two-day forensic science course that is offered to eighth grade students enrolled in Science, Mathematics, and Technology Magnet Schools. Provides sample student activity sheets for the course. (Author/RT)

Lilly, Sherril L.

1989-01-01

225

Elsevier Science  

NSDL National Science Digital Library

Elsevier Science, the scientific communications branch of Reed Elsevier, started its official World-Wide Web and Gopher service which includes: the Elsevier Science Internet Catalogue of Journals and Books; information about - TULIP - The University Licensing Program, a research project Elsevier Science is performing with nine universities in the USA; and, the Proceedings of the WWW'94 Conference (May 25-27, 1994), organized by CERN, Geneva; a number of current awareness services on diverse areas of science.

1998-01-01

226

Science Experiments at Home  

NSDL National Science Digital Library

Professor Bassam Z. Shakhashiri, at the University of Wisconsin - Madison, offers many fun, easy chemistry experiments at this website. Through the utilization of a few household materials, users can learn about pressure, acids and bases, chemiluminescent chemical reactions, and more. The activities are filled with thought provoking questions along with concise explanations about the topic presented. The website provides links to activities dealing with topics in physics as well. Anyone interested in partaking in simple, yet exciting, science experiments with their family and friends at home should visit this website.

2007-12-12

227

Dramatic Science  

ERIC Educational Resources Information Center

The setting: the science classroom. The characters: you and your students. The scene: Your students acting out scientific discoveries, modeling a frog's life cycle, mimicking the transition from liquid to solid. This is "dramatic science", a teaching approach that uses acting techniques to explore and develop young children's ideas about science.…

McGregor, Debbie; Precious, Wendy

2010-01-01

228

Sound Science  

ERIC Educational Resources Information Center

How can a teacher simultaneously teach science concepts through inquiry while helping students learn about the nature of science? After pondering this question in their own teaching, the authors developed a 5E learning cycle lesson (Bybee et al. 2006) that concurrently embeds opportunities for fourth-grade students to (a) learn a science concept,…

Sickel, Aaron J.; Lee, Michele H.; Pareja, Enrique M.

2010-01-01

229

Sublime Science  

ERIC Educational Resources Information Center

One of the shortcomings in most efforts to integrate art and science is that many people have a shallow understanding of art, which inevitably leads to shallow connections between art and science. Coloring drawings of planets, building sculptures of volcanoes, and decorating scientific diagrams are fine activities, but they do not link science and…

Girod, Mark

2007-01-01

230

Safer Science  

ERIC Educational Resources Information Center

This column provides best safety practices for the science classroom and laboratory. In this month's issue, pregnancy policy in the laboratory is discussed. One can't ignore the fact that student and faculty pregnancies--and the resulting potential hazards in the science laboratory--exist at the high school level. Science teachers need to be…

Roy, Ken

2011-01-01

231

Science Facilities  

ERIC Educational Resources Information Center

The National Research Council's "National Science Education Standards" call for science education to be "developmentally appropriate, interesting, and relevant to students' lives, emphasize student understanding through inquiry, and be connected with other school subjects." This description captures the three major trends in science education…

Butin, Dan W.; Biehle, James T.; Motz, LaMoine L.; West, Sandra S.

2009-01-01

232

Digital self excited loop  

US Patent & Trademark Office Database

A process that provides the ability to incorporate a self exciting loop (SEL) algorithm into a digital LLRF system. The present digital SEL provides for conversion from the Cartesian domain to the Polar domain, wherein most signal processing is accomplished, and back to Cartesian. By handling most signal processing in the Polar (phase & amplitude) domain, a perfect amplitude limiter can be realized and simpler logic operations can be used. When operational, cavity recovery from faults will be tuner-less. At high gradients, .about.20 MV/m, like those needed for the upgraded cryomodules, the Lorentz detuning will be many bandwidths, making cavity turn-on problematic with out some tuner based compensation or other algorithmic solution. The present SEL solves this problem and allows cavity recovery from cryogenic trips, wherein cavities have been known to detune 1000's of Hz. Other applications such has He processing can also be implemented in situ without additional electronics.

2012-03-06

233

STUDIES OF EXCITABLE MEMBRANES  

PubMed Central

The neuromuscular junctions and nonjunctional sarcolemmas of mammalian skeletal muscle fibers were studied by conventional thin-section electron microscopy and freeze-fracture techniques. A modified acetylcholinesterase staining procedure that is compatible with light microscopy, conventional thin-section electron microscopy, and freeze-fracture techniques is described. Freeze-fracture replicas were utilized to visualize the internal macromolecular architecture of the nerve terminal membrane, the chemically excitable neuromuscular junction postsynaptic folds, and the electrically excitable nonjunctional sarcolemma. The nerve terminal membrane is characterized by two parallel rows of 100–110-Å particles which may be associated with synpatic vesicle fusion and release. On the postsynpatic folds, irregular rows of densely packed 110–140-Å particles were observed and evidence is assembled which indicates that these large transmembrane macromolecules may represent the morphological correlate for functional acetylcholine receptor activity in mammalian motor endplates. Differences in the size and distribution of particles in mammalian as compared with amphibian and fish postsynaptic junctional membranes are correlated with current biochemical and electron micrograph autoradiographic data. Orthogonal arrays of 60-Å particles were observed in the split postsynaptic sarcolemmas of many diaphragm myofibers. On the basis of differences in the number and distribution of these "square" arrays within the sarcolemmas, two classes of fibers were identified in the diaphragm. Subsequent confirmation of the fiber types as fast- and slow-twitch fibers (Ellisman et al. 1974. J. Cell Biol. 63[2, Pt. 2]:93 a. [Abstr.]) may indicate a possible role for the square arrays in the electrogenic mechanism. Experiments in progress involving specific labeling techniques are expected to permit positive identification of many of these intriguing transmembrane macromolecules.

Rash, John E.; Ellisman, Mark H.

1974-01-01

234

Science and Science Fiction Films.  

ERIC Educational Resources Information Center

Describes an undergraduate physics course for nonscience majors which combines physics with science fiction films. Includes course format, sample module on the concept of momentum, and an appendix with a listing of science fiction films used in this course. (DS)

Dubeck, Leroy W.

1981-01-01

235

Optically excited states in positronium  

NASA Technical Reports Server (NTRS)

Optical excitation are reported of the 1 3S-2 3P transition in positronium, and a second excitation from n=2 to higher n states. The experiment used light from two pulsed dye lasers. Changes in the positronium annihilation rate during and after the laser pulse were used to deduce the excited state populations. The n=2 level was found to be saturable and excitable to a substantial fraction of n=2 positronium to higher levels. Preliminary spectroscopic measurements were performed on n=14 and n=15 positronium.

Howell, R. H.; Ziock, Klaus P.; Magnotta, F.; Dermer, Charles D.; Failor, R. A.; Jones, K. M.

1990-01-01

236

Science Buddies  

NSDL National Science Digital Library

The Science Buddies program pairs a seventh-grade life science class with a second-or third-grade class in a yearlong partnership of science adventures. Over the course of the year these dual-grade learning groups work together on various science explorations--gardening, weather observation, and others--to explore concepts and practice science-process skills such as predicting, gathering, and analyzing data. The program has run for two years at our school and has been truly successful with both students and teachers.

Potenza, Susan A.

2003-01-01

237

Cognitive Science and Science Education  

Microsoft Academic Search

The quality of science education, like mathematics education, is a pervasive concern in educational improvement efforts. The cognitive orientation to the teaching of subject matter provides the context for Carey's discussion of science education. This orientation begins with the idea that to understand something, one must integrate it with already existing knowledge schemata. The paradox of science education is that

Susan Carey

1986-01-01

238

Inclusion, Disabilities, and Informal Science Learning. A CAISE Inquiry Group Report  

ERIC Educational Resources Information Center

Informal science education (ISE) experiences can provide powerful opportunities for people with disabilities to experience and learn about science. When designed to be inclusive, such experiences can lead people with disabilities to feel competent and empowered as science learners, generate excitement and enthusiasm for science, and be equitable…

Reich, Christine; Price, Jeremy; Rubin, Ellen; Steiner, Mary Ann

2010-01-01

239

Crop Science Investigation (CSI) Network  

NSDL National Science Digital Library

Crop Science Investigation (CSI) Network        This site is designed to serve as a clearinghouse of lesson plans and other materials useful for teaching 4-H and FFA youth about crop and soil sciences.  Check out this site for information to use in your classroom, workshops, or 4-H meetings.       As youth become less connected with agriculture, it is essential to teach them about agriculture. A series of workshops, called Crop Science Investigation or CSI was created to help spark the interest of youth to learn about crops and plants.Dig into some interesting facts about Nebraska crops.Learn how crops grow and factors that affect them.Learn about exciting career opportunities related to crop and plant science. The University of Nebraska offers great majors for anyone interested in anything plants!  Check it out!

240

Bridging Science and Policy: The AGU Science Policy Conference  

NASA Astrophysics Data System (ADS)

In recent years, science has become inextricably linked to the political process. As such, it is more important now than ever for science to forge a better relationship with politics, for the health of both science and society. To help meet this need, the American Geophysical Union (AGU) strives to engage its members, shape policy, and inform society about the excitement of Earth and space science and its role in developing solutions for the sustainability of the planet. In June 2013, AGU held its second annual Science Policy Conference in Washington, D.C. The goal of the conference is to provide a new forum for diverse discussions and viewpoints on the challenges and opportunities of science policy, with a focus on applications of Earth and space science that serve local, national, and international communities. The meeting brought together more than 300 scientists, policy makers, industry professionals, members of the press, and other stakeholders to discuss the topics concerning the Arctic, climate change, oceans, energy, technology and infrastructure, and natural hazards science as they relate to challenges impacting society. Sessions such as 'The Water-Energy Nexus,' 'Potential for Megadisasters,' 'The Changing Ocean and Impacts on Human Health,' and 'Drowning and Drought: Agricultural Impacts of Climate Change' are examples of some of the intriguing and timely science policy issues addressed at the conference. The findings from the conference were used to develop a summary report. The report highlights key facts and figures to be used as a resource in discussions with policy makers and other stakeholders regarding the conference topics. This presentation will discuss the goals and outcomes of the conference and how the event represents one of the many ways AGU is approaching its 'Science and Society' priority objective as part of the Union's strategic plan; namely by increasing the effectiveness and recognition of AGU among policy makers as an authoritative source of integrated, interdisciplinary Earth and space science information.

Hankin, E. R.; Uhlenbrock, K.; Landau, E. A.

2013-12-01

241

ALMA in Early Science (Cycles 0 and 1)  

NASA Astrophysics Data System (ADS)

ALMA's initial PI-driven science campaign ("Cycle 0") is now well underway and the deadline for the next round of Early Science ("Cycle 1") is this summer. Cycle 0 has already produced exciting results and ALMA has carried out an exciting Science Verification program. I will give an update on ALMA construction and operations and show early science highlights. I will review the capabilities available to the community in ALMA Cycle 1, which include and expanded number of antennas, increased correlator flexibility, and sensitivity to extended structure thanks to the inclusion of the ACA.

Sheth, Kartik

2012-05-01

242

Science Sampler: Making movies in the classroom  

NSDL National Science Digital Library

When you overhear students talking excitedly about video games, the internet, television, or movies, do you ever wish that they could get that excited about what was happening in the science classroom? By using simple software, students can plan, shoot, and edit movies of their own design! In this fascinating activity, students create a documentary on a famous earthquake, volcanic eruption, tsunami, hurricane, or other natural disaster as they put their own unique spin on the theory of plate tectonics.

Richards, Lauren

2006-07-01

243

GEOTROPIC EXCITATION IN HELIX  

PubMed Central

Rotation of an inclined surface on which Helix is creeping straight upward, such that the axis of the animal is turned at a right angle to its previous position, but in the same plane, leads to negatively geotropic orientation after a measurable latent period or reaction time. The duration of the latent period is a function of the slope of the surface. The magnitude of the standard deviation of the mean latent period is directly proportional to the mean latent period itself, so that the relative variability of response is constant. The dependence of reaction time upon extent of displacement from symmetrical orientation in the gravitational field is found also by tilting the supporting surface, without rotation in the animal's own plane. On slopes up to 55°, the relation between latent period and the sine of the slope is hyperbolic; above this inclination, the latent period sharply declines. This change in the curve is not affected by the attachment of moderate loads to the snail's shell (up to 1/3 of its own mass), and is probably a consequence of loss of passive stable equilibrium when rotated. When added loads do not too greatly extend the snail's anterior musculature, the latent period for the geotropic reaction is decreased, and, proportionately, its ?. These facts are discussed from the standpoint that geotropic excitation in these gasteropods is due to impressed muscle-tensions.

Hoagland, H.; Crozier, W. J.

1931-01-01

244

Science Shorts: More Than One Way to Investigate  

NSDL National Science Digital Library

An exciting element of science fairs is that they give students the opportunity to explore various interests through scientific investigation. Many students, however, mistakenly think that all investigations are experiments. This lesson can help broaden s

Davis, Kimberly J.; Coskie, Tracy L.

2007-12-01

245

CLSI: Cool Life Science Investigations  

NSDL National Science Digital Library

With the number of popular medical and forensics programs on television and many references in the media today, even elementary students can comfortably throw around terms such as cells, DNA, and artificial products. However, their questions on these topics often go unanswered, or they are left with misinformation regarding these concepts. As a result, a group of university science educators and the resource coordinator for an elementary school gifted program teemed up to create accurate, developmentally appropriate, and exciting experiences with these topics for students in grades K-5. The result of this collaborative effort was an after-school science "tradeshow," which is described here.

Falsarella, Carell; Marek, Edmund A.; Mccann, Florence F.; Pederson, Jon E.

2007-12-01

246

Get excited: Reappraising pre-performance anxiety as excitement.  

PubMed

Individuals often feel anxious in anticipation of tasks such as speaking in public or meeting with a boss. I find that an overwhelming majority of people believe trying to calm down is the best way to cope with pre-performance anxiety. However, across several studies involving karaoke singing, public speaking, and math performance, I investigate an alternative strategy: reappraising anxiety as excitement. Compared with those who attempt to calm down, individuals who reappraise their anxious arousal as excitement feel more excited and perform better. Individuals can reappraise anxiety as excitement using minimal strategies such as self-talk (e.g., saying "I am excited" out loud) or simple messages (e.g., "get excited"), which lead them to feel more excited, adopt an opportunity mind-set (as opposed to a threat mind-set), and improve their subsequent performance. These findings suggest the importance of arousal congruency during the emotional reappraisal process. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:24364682

Brooks, Alison Wood

2014-06-01

247

Astronomical Approach to Physical Science Curriculum  

NASA Astrophysics Data System (ADS)

The Astronomical Approach to Physical Science Curriculum (AAPS Curriculum) is an innovative curriculum that incorporates an astronomy theme into an inquiry-based physical science curriculum for pre-service, elementary school teachers. Many physical science courses are a non-cohesive collection of topics required for the state teaching license. Through the use of astronomy and space science examples, the AAPS Curriculum will have a coherent theme that ties the wide variety of physical science topics together and provides many real world applications for the topics covered in the course. This new curriculum will incorporate the applications of knowledge to complete the learning cycle-exploration, concept introduction, application. Astronomy and space science applications will be emphasized throughout the curriculum. The theme of astronomy was chosen to prepare elementary school teachers for teaching astronomy and space science in their classroom, as this is a topic in which many school children are consistently interested. Since astronomy is a topic that can be used as a springboard to teach many other areas of study, we want teachers who are knowledgeable in topics of astronomy so they are capable of preparing creative lessons throughout their entire curriculum that are exciting to their students. The AAPS Curriculum will train college students to become teachers who are comfortable with physical science and astronomy topics and who are excited to teach these topics in their classroom. Funding for this work is provided by the IDEAS grant program of the Space Telescope Science Institute.

Manning, H. L. K.; Churukian, A. D.

2004-11-01

248

Reading Science  

ERIC Educational Resources Information Center

Reading the average science textbook, one is struck with a question: Why would people devote their lives to the study of a subject as dry as the Sahara Desert? Students in science classes only need to be let in on the great secret of science. It is fun and full of the stuff in page-turner novels--intrigue, mystery, romance, and sometimes just dumb…

Carlson, Kenneth

2005-01-01

249

Deconstructing science  

NASA Astrophysics Data System (ADS)

In this paper I expand on the premises of Jesse Bazzul's thesis in his paper, Neoliberal ideology, global capitalism, and science education: engaging the question of subjectivity, exploring the implications of the ideologies within the culturally emerging logic of science exposes the incommensurability of intents and purposes in its methods and epistemology. I argue that science needs to acknowledge the subjectivity at its core to make space for non-absolute agents and new fields of study.

Trifonas, Peter Pericles

2012-12-01

250

Exploration of laser-excitation of Kr  

NASA Astrophysics Data System (ADS)

Isotopic detection of the isotopes of Krypton has many important applications in atmospheric science [Zheng-Tian Lu and Peter Mueller, Chapter 4 - Atom Trap Trace Analysis of Rare Noble Gas Isotopes, Advances in Atomic, Molecular, and Optical Physics, Volume 58, 2010, Pages 173-205]. It has been shown that laser cooling and trapping of metastable Kr (5s,[3/2]2) is an effective means to achieve detection efficiencies of 1 part in10^12. A limiting factor in these studies is the production of metastable Kr, which is currently implemented using an RF discharge [C. Y. Chen et al., Beam of metastable krypton atoms extracted from a rf-driven discharge, Review of scientific instruments, Volume 72, No.1, 2001]. Here we report on the success of several experimental attempts at laser-based excitation.

Rupasinghe, Priyanka; Yang, Tao; Shafer-Ray, Neil

2011-06-01

251

Science Fair  

NSDL National Science Digital Library

Your task is to design a science fair project by choosing from a list of questions that I have provided. The questions will narrow down your topic to a specific area in science, however the ultimate topic of your project is up to you! Make sure to pick an area of science that you are interested in, this should be fun! Enjoy! Guidelines For The Project: You may work in pairs, or by yourself. There are to be no more than two people working together on a single project. Partners must be in the same period science class. Research will be done on the project, a works cited page must also ...

Baumes, Ms.

2008-05-15

252

Science Notes.  

ERIC Educational Resources Information Center

Contains 31 activities and experiments from the biological and physical sciences. Addresses such areas as reproduction, biotechnology, ecology, proteins, nitrates, aerosols, metal crystallinity, circuit boards, and photoswitching. (ML)

School Science Review, 1987

1987-01-01

253

Sublime Science  

NSDL National Science Digital Library

One of the shortcomings in most efforts to integrate art and science is that many of us have a shallow understanding of art, which inevitably leads to shallow connections between art and science. Coloring drawings of planets, building sculptures of volcanoes, and decorating scientific diagrams are fine activities, but they do not link science and art in powerful ways. One way to more deeply connect art and science is to consider art in its more broad form--aesthetics, and in this case, the sublime.

Girod, Mark

2007-02-01

254

The exciting thing about recombinant DNA, Victor McElhenySite: DNA Interactive (www.dnai.org)  

NSDL National Science Digital Library

` Victor McElheny DNAi Location:Manipulation>Revolution>players>The controversy A new world of exploration Former science journalist Victor McElheny muses on the excitement that surrounded the new genetic technology.

2008-03-26

255

Vibrational Excitation in Molecular Collisions  

NASA Astrophysics Data System (ADS)

The collision energy dependence of the total cross sections for state resolved translation to vibration energy transfer was measured for several neutral systems. Measurements were made for vibrationally inelastic collisions of iodine with helium, neon, and hydrogen isotopes, as well as collisions of aniline and paradifluorobenzene with helium, all in the thermal energy range. Our new experimental technique uses pulsed supersonic molecular beams for initial state selection, crossed at a variable intersection angle for kinematic, continuously tunable collision energy selection. The scattered products are state-selectively detected in the intersection region by laser induced fluoroscence. The iodine cross section energy dependences are approximately linear, quadratic, and cubic for v = 0 to 1, 2, and 3 excitations respectively, as expected from a classical-quantal correspondence principle model. Extreme mode specificity was observed in the polyatoms as only 3 of about 20 energetically accessible vibrations were observed to be collisionally excited. In aniline, the 2 lowest frequency modes were excited. The cross section for single quantum excitations of the inversion mode of the amine group is a strongly decreasing function over the 20 to 250 meV collision energy range. The other observed mode, an out-of-plane bend of the amine group shows a linear onset at threshold for single quantum excitations. The only vibration excited in paradifluorobenzene was the lowest frequency, out-of-plane fluorine bend. Excitation of 1 and 2 quanta was observed. The cross sections both have approximately linear onset at threshold.

Hall, Gregory

256

Radioactivity Induced by Nuclear Excitation I. Excitation by Neutrons  

Microsoft Academic Search

It is shown that the 4.1-hr. period of indium can be produced by nuclear excitation of indium and is to be attributed to an excited metastable state, In115,* of the stable In115. This result is obtained by studying the radioactivity produced in indium by neutrons of different energy distributions and by studying the chain reactions produced in cadmium by fast

M. Goldhaber; R. D. Hill; Leo Szilard

1939-01-01

257

Localized excitations and their thresholds  

PubMed

We propose a numerical method for identifying localized excitations in discrete nonlinear Schrodinger type models. This methodology, based on the application of a nonlinear iterative version of the Rayleigh-Ritz variational principle yields breather excitations in a very fast and efficient way in one or higher spatial dimensions. The typical convergence properties of the method are found to be super-linear. The usefulness of this technique is illustrated by studying the properties of the recently developed theoretical criteria for the excitation power thresholds for nonlinear modes. PMID:11088275

Kevrekidis; Rasmussen; Bishop

2000-04-01

258

Science Signaling Podcast: 06 May 2008  

NSDL National Science Digital Library

This conversation is about research highlighted in Editors' Choice titled, "What’s So Exciting About Glia?" The highlighted article is R. Káradóttir, N. B. Hamilton, Y. Bakiri, D. Attwell, Spiking and nonspiking classes of oligodendrocyte precursor glia in CNS white matter. Nat. Neurosci. 11, 450–456 (2008). (Length: 6 min; file size: 2.61 MB; file format: mp3; location: http://podcasts.aaas.org/science_signaling/ScienceSignaling_080506.mp3)

Elizabeth M. Adler (American Association for the Advancement of Science;Science Signaling REV); Annalisa M. VanHook (American Association for the Advancement of Science;Science Signaling REV)

2008-05-06

259

Earth Sciences Division annual report 1989  

SciTech Connect

This Annual Report presents summaries of selected representative research activities from Lawrence Berkeley Laboratory grouped according to the principal disciplines of the Earth Sciences Division: Reservoir Engineering and Hydrology, Geology and Geochemistry, and Geophysics and Geomechanics. We are proud to be able to bring you this report, which we hope will convey not only a description of the Division's scientific activities but also a sense of the enthusiasm and excitement present today in the Earth Sciences.

Not Available

1990-06-01

260

The sciences of science communication.  

PubMed

The May 2012 Sackler Colloquium on "The Science of Science Communication" brought together scientists with research to communicate and scientists whose research could facilitate that communication. The latter include decision scientists who can identify the scientific results that an audience needs to know, from among all of the scientific results that it would be nice to know; behavioral scientists who can design ways to convey those results and then evaluate the success of those attempts; and social scientists who can create the channels needed for trustworthy communications. This overview offers an introduction to these communication sciences and their roles in science-based communication programs. PMID:23942125

Fischhoff, Baruch

2013-08-20

261

Bad Science  

NSDL National Science Digital Library

This website is designed to sensitize teachers and students to examples of bad science taught in schools and universities, and offered in popular articles and textbooks. Sections include Bad Astronomy, Bad Chemistry, and Bad Meteorology. As an example of bad science, the Pathetic Fallacy, which is the mistake of attributing human qualities to events or inanimate objects, is explained.

Fraser, Alistair

262

Life sciences  

SciTech Connect

This document is the 1989--1990 Annual Report for the Life Sciences Divisions of the University of California/Lawrence Berkeley Laboratory. Specific progress reports are included for the Cell and Molecular Biology Division, the Research Medicine and Radiation Biophysics Division (including the Advanced Light Source Life Sciences Center), and the Chemical Biodynamics Division. 450 refs., 46 figs. (MHB)

Day, L. (ed.)

1991-04-01

263

"Children's Science"  

ERIC Educational Resources Information Center

The revamped New Zealand curriculum emphasises "scientific literacy for all students" and provides teachers with an opportunity to promote science as an integral element of the primary school curriculum. Exploring and explaining the natural world in primary science can provide authentic contexts for the development of knowledge, skills, and…

Milne, Ian

2007-01-01

264

Analytical Sciences  

NSDL National Science Digital Library

From the Japan Society for Analytical Chemistry, Analytical Sciences is a completely free journal covering topics related to "the theory and practice of analytical sciences, including fundamental and applied, inorganic and organic, wet chemical and instrumental methods." Full-text content is available beginning 1998 (Vol 14); Table of Contents begins December, 1992 (Vol 8).

265

Soundsational Science  

ERIC Educational Resources Information Center

The science of sound helps students learn that sound is energy traveling in waves as vibrations transfer the energy through various media: solids, liquids, and gases. In addition to learning about the physical science of sound, students can learn about the sounds of different animal species: how sounds contribute to animals' survival, and how…

Carrier, Sarah J.; Scott, Catherine Marie; Hall, Debra T.

2012-01-01

266

Shrinking Science.  

ERIC Educational Resources Information Center

Describes an activity based on shrinkable thermoplastics in which students explore the percentage of shrinkage of a plastic ruler when it is heated. Includes science content knowledge behind the shrink, national science education standards related to this activity, and a complete guide. (KHR)

Goates, Wayne

2002-01-01

267

Science Notes.  

ERIC Educational Resources Information Center

Presents 31 science activities for use with high school or college science classes. Topics included are: chromatography, ecology, invertebrates, enzymes, genetics, botany, creep, crystals, diffusion, computer interfaces, acid rain, teaching techniques, chemical reactions, waves, electric fields, rainbows, electricity, magnetic fields, and a Pitot…

Murray, A. J. S.; And Others

1988-01-01

268

Talking Science  

ERIC Educational Resources Information Center

Science is a social process--one that involves particular ways of talking, reasoning, observing, analyzing, and writing, which often have meaning only when shared within the scientific community. Discussions are one of the best ways to help students learn to "talk science" and construct understanding in a social context. Since inquiry is an…

Shwartz, Yael; Weizman, Ayelet; Fortus, David; Sutherland, LeeAnn; Merrit, Joi; Krajcik, Joe

2009-01-01

269

Legendary Science.  

ERIC Educational Resources Information Center

Spiders and insects are studied in both Navajo Studies and science classes at a middle school in New Mexico. In Navajo Studies, students learn the names of ground-dwelling insects and the connection between those names and traditional Navajo stories. In science class, students study arthropods to illustrate taxonomy of life, trophic and biological…

O'Keefe, William A.; Joe, Jimson

1998-01-01

270

Information Science.  

ERIC Educational Resources Information Center

Presents personal analysis of information science as a field of scientific inquiry and professional practice that has evolved over the past half-century. Examines origin of information science in respect to problems of the information explosion, social role of field, nature of "information," structure of field in terms of problems addressed,…

Saracevic, Tefko

1999-01-01

271

Information Science  

Microsoft Academic Search

This essay is a personal analysis of information science as a field of scientific inquiry and professional practice that has evolved over the past half-century. Various sec- tions examine the origin of information science in re- spect to the problems of information explosion; the so- cial role of the field; the nature of \\

Tefko Saracevic

1999-01-01

272

Science Careers  

NSDL National Science Digital Library

Let's say you're looking for a job in biotechnology someplace south of Monterey, but north of Santa Barbara. The Science Careers website can help, and it also features high-quality commentary on the state of the science workplace environment. The site is dedicated to "furthering careers in science and technology" and the heart and soul of this site is the science job database. Visitors can search jobs by keywords, U.S. regions, continent, or even perform a more advanced search. On the left-hand side of the site, visitors will find career-focused articles with titles like "Mind Matters: A Low Stress Semester", "Dealing with Debt", and "The Evolving Postdoctoral Experience". Also, visitors can check out the "Science Careers Forum" to ask questions about future employment opportunities and career development.

2009-09-14

273

Multiphonon excitations in 62Zn  

NASA Astrophysics Data System (ADS)

We studied excited states in 62Zn up to an excitation energy of 5.5 MeV via the 61Ni( 3He, 2n ?) reaction at the Cologne Tandem accelerator with the high-efficiency HORUS cube spectrometer. We identified several multi-phonon excitations, especially two fragments of the one-phonon mixed-symmetry state 21,MS+ based on effective M1 and E2 transition strengths. The quantities were obtained from ?? angular correlation and Doppler-shift measurements. Shell-model calculations performed for 62Zn give clear support for the fragmentation of the one-phonon mixed-symmetry 21,MS+ state. The assumption of 62Zn being a vibrator-like nucleus is supported by calculations of excitation energies and E2 and M1 transition strengths within the U(5) limit of the neutron-proton Interacting Boson Model.

Albers, M.; Mücher, D.; Bernards, C.; Blazhev, A.; Fransen, C.; Heinze, S.; Jolie, J.; Lisetskiy, A.; Petkov, P.; Radeck, D.; Zell, K. O.

2010-12-01

274

Collisional excitation of interstellar formaldehyde  

NASA Technical Reports Server (NTRS)

Previous calculations for rates of excitation of ortho-H2CO by collisions with He have been extended to higher rotational levels and kinetic temperatures to 80 K. Rates for para-H2CO have also been computed. Pressure-broadening widths for several spectral lines have been obtained from these calculations and are found to agree with recent data within the experimental uncertainty of 10%. Excitation of formaldehyde by collisions with H2 molecules is also discussed.

Green, S.; Garrison, B. J.; Lester, W. A., Jr.; Miller, W. H.

1978-01-01

275

Science Sampler: A (minty) fresh approach to science fair projects  

NSDL National Science Digital Library

Many students are excited at the prospect of doing a science fair project, but they don't know how to go about asking an appropriate question or designing an experiment to answer their question. This class activity allows students to quickly "do" a class science fair project in order to see how it's done. It's also a great way to introduce concepts of controlling variables and testing multiple subjects using an inexpensive breath mint. Even if you do not do science fair projects with your class, this is a terrific activity for the beginning of the year as an introduction to the process of scientific inquiry. Students discover how to ask a simple question and collect data to answer it in a step-by-step fashion.

Balter, Nancy

2007-02-01

276

Electrostatic Tuning of Cellular Excitability  

PubMed Central

Abstract Voltage-gated ion channels regulate the electric activity of excitable tissues, such as the heart and brain. Therefore, treatment for conditions of disturbed excitability is often based on drugs that target ion channels. In this study of a voltage-gated K channel, we propose what we believe to be a novel pharmacological mechanism for how to regulate channel activity. Charged lipophilic substances can tune channel opening, and consequently excitability, by an electrostatic interaction with the channel's voltage sensors. The direction of the effect depends on the charge of the substance. This was shown by three compounds sharing an arachidonyl backbone but bearing different charge: arachidonic acid, methyl arachidonate, and arachidonyl amine. Computer simulations of membrane excitability showed that small changes in the voltage dependence of Na and K channels have prominent impact on excitability and the tendency for repetitive firing. For instance, a shift in the voltage dependence of a K channel with ?5 or +5 mV corresponds to a threefold increase or decrease in K channel density, respectively. We suggest that electrostatic tuning of ion channel activity constitutes a novel and powerful pharmacological approach with which to affect cellular excitability.

Borjesson, Sara I.; Parkkari, Teija; Hammarstrom, Sven; Elinder, Fredrik

2010-01-01

277

Science Indicators and Science Priorities.  

ERIC Educational Resources Information Center

Discusses science/society interface and difficulties involved in developing realistic science indicators. Topics include: intrinsic vs. extrinsic indicators; four problems society faces as a result of technological activities (toxic chemicals, radioactive wastes, auto safety, cancer); research and development (R&D) priorities; international…

Brooks, Harvey

1982-01-01

278

Science Policy: Pangs of Science  

ERIC Educational Resources Information Center

Presented is the prepared text of a public lecture given by the president of the National Academy of Sciences. Dr. Handler attempts to articulate the state of science today. He deals with such issues as nuclear power and genetic engineering. (MDR)

Handler, Philip

1978-01-01

279

The policy sciences as science  

Microsoft Academic Search

The preceding evaluation of the policy sciences by Schneider, Stevens, and Tornatzky is based on a rather narrow conception of science that emphasizes quantitative and rigorous methods. It overlooks the limitations of such methods, as revealed by the results of applications, and certain adjustments to these limitations. The latter include the adoption of more modest but realizable aspirations and the

Ronald D. Brunner

1982-01-01

280

Science packages  

NASA Astrophysics Data System (ADS)

Primary science teachers in Scotland have a new updating method at their disposal with the launch of a package of CDi (Compact Discs Interactive) materials developed by the BBC and the Scottish Office. These were a response to the claim that many primary teachers felt they had been inadequately trained in science and lacked the confidence to teach it properly. Consequently they felt the need for more in-service training to equip them with the personal understanding required. The pack contains five disks and a printed user's guide divided up as follows: disk 1 Investigations; disk 2 Developing understanding; disks 3,4,5 Primary Science staff development videos. It was produced by the Scottish Interactive Technology Centre (Moray House Institute) and is available from BBC Education at £149.99 including VAT. Free Internet distribution of science education materials has also begun as part of the Global Schoolhouse (GSH) scheme. The US National Science Teachers' Association (NSTA) and Microsoft Corporation are making available field-tested comprehensive curriculum material including 'Micro-units' on more than 80 topics in biology, chemistry, earth and space science and physics. The latter are the work of the Scope, Sequence and Coordination of High School Science project, which can be found at http://www.gsh.org/NSTA_SSandC/. More information on NSTA can be obtained from its Web site at http://www.nsta.org.

1997-01-01

281

National Science Foundation: Science Nation  

NSDL National Science Digital Library

Billed as "The Online Magazine That's All About Science for the People", the online magazine Science Nation reports on important science breakthroughs. Created by the National Science Foundation, the site reports on scientific and technological developments by using video clips, first-hand reporting, and well-written articles. On the homepage, visitors can take in their latest report, and then move on down to the "Science Nation Topics" area. Here they will find reports on tornadoes, new technologies for the visually handicapped, and the effect that climate change will have on Emperor penguin populations in Antarctica. Each topic is accompanied by related images and links to additional websites of note. Finally, visitors can also sign up to receive updates from the site via email and they are welcome to send along their feedback.

282

Evaluation of the Long-Term Impact of a University High School Summer Science Program on Students' Interest and Perceived Abilities in Science  

ERIC Educational Resources Information Center

Many biomedical research universities have established outreach programs for precollege students and teachers and partnerships with local school districts to help meet the challenges of science education reform. Science outreach programs held in university research facilities can make science more exciting and innovative for high school students…

Markowitz, Dina G.

2004-01-01

283

Exhausting Science  

NSDL National Science Digital Library

The fume hood: You know what it is, but have you ever used it? And if a safety issue arose, would you know what to do? Unfortunately, fume hoods are frequently included in a science room just for show. Little thought is often given to how they should be used or maintained. It is important for science teachers to understand and regularly inspect fume hoods in their classrooms and laboratories. In this article, the author discusses a few considerations for design, inspection, use, and maintenance of fume hoods in a science lab and classroom. Read on for an "exhaustive" look at this safety device!

Mandt, Douglas

2009-01-01

284

Be/X-Ray Pulsar Binary Science with LOFT  

NASA Technical Reports Server (NTRS)

Accretion disks are ubiquitous in astronomical sources. Accretion powered pulsars are a good test bed for accretion disk physics, because unlike for other objects, the spin of the neutron star is directly observable allowing us to see the effects of angular momentum transfer onto the pulsar. The combination of a sensitive wide-field monitor and the large area detector on LOFT will enable new detailed studies of accretion powered pulsars which I will review. RXTE observations have shown an unusually high number of Be/X-ray pulsar binaries in the SMC. Unlike binaries in the Milky Way, these systems are all at the same distance, allowing detailed population studies using the sensitive LOFT WFM, potentially providing connections to star formation episodes. For Galactic accreting pulsar systems, LOFT will allow measurement of spectral variations within individual pulses, mapping the accretion column in detail for the first time. LOFT will also provide better constraints on magnetic fields in accreting pulsars, allowing measurements of cyclotron features, observations of transitions into the centrifugal inhibition regime, and monitoring of spin-up rate vs flux correlations. Coordinated multi-wavelength observations are crucial to extracting the best science from LOFT from these and numerous other objects.

Wilson-Hodge, Colleen A.

2011-01-01

285

Adventures in Rocket Science. EG-2007-12-179-MSFC  

ERIC Educational Resources Information Center

This guide was prepared as a tool useful for informal education venues (4-H, Boys and Girls Clubs, Boy Scouts, Girl Scouts, etc.), science clubs and related programs, and can be adopted for formal education settings. An exciting and productive study in rocket science can be implemented using the selected activities for the above-mentioned…

Huegele, Vince; Hill, Kristy; Terry, Brenda

2008-01-01

286

"Celebrate Science" Has Formula for Hands-On Learning  

ERIC Educational Resources Information Center

Cost-effective, easily replicated program is a win-win situation for high schoolers who teach science and for their elementary students. The thank-you letter from Leslie, a grade-schooler in San Diego County's Ramona Unified School District, speaks volumes about the excitement generated by "Celebrate Science"--an innovative, standards-based…

Brydolf, Carol

2012-01-01

287

Teaching Creativity and Inventive Problem Solving in Science  

Microsoft Academic Search

Engaging learners in the excitement of science, helping them discover the value of evidence- based reasoning and higher-order cognitive skills, and teaching them to become creative problem solvers have long been goals of science education reformers. But the means to achieve these goals, especially methods to promote creative thinking in scientific problem solving, have not become widely known or used.

Robert L. DeHaan

2009-01-01

288

Science Shorts: More than One Way to Investigate  

ERIC Educational Resources Information Center

An exciting element of science fairs is that they give students the opportunity to explore various interests through scientific investigation. Many students, however, mistakenly think that all investigations are experiments. This lesson can help broaden students' conceptions of science. (Contains 1 resource.)

Coskie, Tracy L.; Davis, Kimberly J.

2007-01-01

289

Toolkit: Becoming a Science, Technology, Engineering, and Math (STEM) Mentor  

ERIC Educational Resources Information Center

President Obama has recognized the need to move students from the middle to the top of the pack in math and science as a national priority. Mentorship is often cited as a key strategy for exciting, supporting, and keeping students and young scientists and engineers in the fields of science, technology, engineering, and math (STEM). This is…

Corporation for National and Community Service, 2010

2010-01-01

290

HEASARC - The High Energy Astrophysics Science Archive Research Center  

NASA Technical Reports Server (NTRS)

The High Energy Astrophysics Science Archive Research Center (HEASARC) is NASA's archive for high-energy astrophysics and cosmic microwave background (CMB) data, supporting the broad science goals of NASA's Physics of the Cosmos theme. It provides vital scientific infrastructure to the community by standardizing science data formats and analysis programs, providing open access to NASA resources, and implementing powerful archive interfaces. Over the next five years the HEASARC will ingest observations from up to 12 operating missions, while serving data from these and over 30 archival missions to the community. The HEASARC archive presently contains over 37 TB of data, and will contain over 60 TB by the end of 2014. The HEASARC continues to secure major cost savings for NASA missions, providing a reusable mission-independent framework for reducing, analyzing, and archiving data. This approach was recognized in the NRC Portals to the Universe report (2007) as one of the HEASARC's great strengths. This poster describes the past and current activities of the HEASARC and our anticipated developments in coming years. These include preparations to support upcoming high energy missions (NuSTAR, Astro-H, GEMS) and ground-based and sub-orbital CMB experiments, as well as continued support of missions currently operating (Chandra, Fermi, RXTE, Suzaku, Swift, XMM-Newton and INTEGRAL). In 2012 the HEASARC (which now includes LAMBDA) will support the final nine-year WMAP data release. The HEASARC is also upgrading its archive querying and retrieval software with the new Xamin system in early release - and building on opportunities afforded by the growth of the Virtual Observatory and recent developments in virtual environments and cloud computing.

Smale, Alan P.

2011-01-01

291

How Do You Choose Science Trade Books?  

NSDL National Science Digital Library

Using trade books is one strategy that has the potential to increase students' interest and achievement in science; to enhance scientific and technological literacy; and to help open doors to exciting careers. Because there are over 120,000 children's tra

Dudley, Ann P.; Williams, Christy S.; Rice, Diana C.

2001-03-01

292

Safer Science: Building Safety in Foreign Language  

NSDL National Science Digital Library

A school is about to undergo major renovations and new construction to handle a growing student population. So some science classes and labs are assigned to other parts of the building temporarily. Most teachers are excited about the opportunity to help d

Roy, Ken

2011-01-01

293

Science in a Multi-Age Environment.  

ERIC Educational Resources Information Center

This paper outlines the implementation of a Science Rally held at Palm Beach State Primary School (Australia) which has a high proportion of disadvantaged families. Fostering the principles of multi-age grouping in primary schools, the rally aimed at engaging children in meaningful and exciting activities in a non threatening and success oriented…

Stir, John W.; And Others

294

Science Teaching to Fire the Imagination.  

ERIC Educational Resources Information Center

Presents a range of exciting ideas for encouraging active learning, for illuminating new concepts, and for making science lessons fun. Topics include modeling, matter, heat, diffusion, changes of state, heat transfer, energy changes, atomic structure, waves, gravity, enzymes, and habitats. (JRH)

Sandford, Diana; Fleetwood, Julie

1997-01-01

295

Tricky Science  

NSDL National Science Digital Library

Science demonstrations can be excellent tools for capturing students' attention. This "magic trick" involves Super Gel (sodium polyacrylate) and "disappearing" water. This inquiry-based activity is designed to stimulate critical thinking and develop students' powers of observation.

Stewart, Mike

2004-09-01

296

Scuba Science.  

ERIC Educational Resources Information Center

Introduces an integrated unit on scuba science. Studies oxygen in kinetic theory, Boyle's law, Charles's law, Dalton's law, human circulatory and respiratory systems, and diving dangers such as decompression sickness. (YDS)

Glickstein, Neil

2000-01-01

297

Forensic Science.  

ERIC Educational Resources Information Center

Presents a review of articles appealing to forensic practitioners. Topics include: drugs and poisons, forensic biochemistry, and trace evidence. Lists noteworthy books published on forensic science topics since 1986. (MVL)

Brettell, T. A.; Saferstein, R.

1989-01-01

298

Science: Multimedia  

NSDL National Science Digital Library

With coverage of food science, the Neanderthal genome, and oil extraction via algae, the Science multimedia page has something for just about everyone. At the top of the page, visitors will find the "Science Podcast". Visitors are encouraged to sign up to the podcast's RSS feed, and they can also listen in to previous installments. The "Images and Slide Shows" area is a delight for the senses, as it features photo essays with audio commentary on HIV/AIDS in Eastern Europe and "How Astronomers Have Fun (and Nearly Die Trying)". If that isn't enough, head on over to the "Interactives" area, where one can learn about plant genomes via a series of video clips, illustrations, and scientific drawings. The other interactive features here cover sea urchins and the human gut. Science educators and writers will find the site particularly useful, though everyone with a curious spirit will appreciate it.

2010-08-20

299

Science Management.  

National Technical Information Service (NTIS)

The book presents a general survey of science management both in the USSR and abroad. The problems of scientific research management within the limits of a research team laboratory, institute department, and the national economy as a whole are considered....

G. M. Dobrov

1974-01-01

300

Halloween Science  

NSDL National Science Digital Library

Students may well have the usual "bigger is better" conception about comparing different items. Pumpkins are the perfect object to help engage students in investigative science and answer most of their questions by direct observation.

Konicek-Moran, Richard

2010-03-12

301

Science Notes.  

ERIC Educational Resources Information Center

Describes 20 teaching activities and experiments appropriate for use with various secondary school science classes. Instructional activities include the study of catalase, raising bees, a game about equilibrium, spectrometers, lead iodide, resonance, graphing, and electromagnetic waves. (TW)

School Science Review, 1987

1987-01-01

302

Overnight Science.  

ERIC Educational Resources Information Center

Outlines objectives for an elementary science camping program and summarizes general operational procedures. Campsite activities related to such topics as microorganisms, eye and sight, nature trails, bees, carpentry, and astronomy are described. (DS)

Smith, Nancy N.; Stahl, Robert J.

1981-01-01

303

Science Scenarios  

NSDL National Science Digital Library

In recent years, the scientific community has emphasized the importance of making science content more meaningful to high school students. One effective technique that helps teachers facilitate student learning is role-playing. By participating in role-pl

Cronin-Jones, Linda

2000-04-01

304

Communicating Science  

USGS Publications Warehouse

For science to have an impact, it must be communicated and easily accessible. The USGS National Wetlands Research Center communicates its research findings through several ways: publishing, the Web, the library, and education and outreach.

Farris, Gaye S.

2005-01-01

305

Forensic Science  

ERIC Educational Resources Information Center

Summarizes the type of work carried out by forensic chemists and the minimum qualification needed for appointment. Indicates that there are eight Home Office regional forensic science laboratories in addition to the Central Research Establishment at Aldermaston. (CC)

Cobb, P. G. W.

1973-01-01

306

Dismal Science  

PubMed Central

“No prediction, no science.” By this standard, the past year has not been kind to the pretensions of “economic science,” Nobel prizes notwithstanding. The issue is more than semantic. As Neil Postman (1992) pointed out, sciences study natural processes that repeat themselves under constant conditions. The social disciplines study practices of human communities that are embedded in history. There are no constant conditions; it is impossible to step into the same river twice (Heraclitus). “Physics envy” has led mainstream economic theorists to attempt to understand their discipline through methods and models borrowed from the natural sciences. (By unfortunate coincidence, these have reinforced a certain class of ideological preconceptions and associated economic interests.) Today the results of this methodological mismatch speak for themselves.

Evans, Robert G.

2009-01-01

307

Science Weekly.  

ERIC Educational Resources Information Center

Reviews the space classroom that would have been conducted by Christa McAuliffe during the space shuttle flight. Includes lab activities, word puzzles, vocabulary lists, and graph reading exercises for elementary science students. (ML)

Science and Children, 1986

1986-01-01

308

Science Notes.  

ERIC Educational Resources Information Center

Presents 23 experiments, activities, field projects and computer programs in the biological and physical sciences. Instructional procedures, experimental designs, materials, and background information are suggested. Topics include fluid mechanics, electricity, crystals, arthropods, limpets, acid neutralization, and software evaluation. (ML)

School Science Review, 1985

1985-01-01

309

Science Notes.  

ERIC Educational Resources Information Center

Twenty-two activities are presented. Topics include: acid rain, microcomputers, fish farming, school-industry research projects, enzymes, equilibrium, assessment, science equipment, logic, Archimedes principle, electronics, optics, and statistics. (CW)

School Science Review, 1989

1989-01-01

310

Space Sciences  

NSDL National Science Digital Library

The latest addition to the Office of Naval Research's Science & Technology Focus site (last mentioned in March 29, 2002 Scout Report) is the Space Sciences Page. The site contains the Observing the Sky link, which has easily read information, photographs, and illustrations on earth rotation, orbit, seasons, observing stars, and more. The Navy & Satellites link describes the Navy's role in launching satellites and how that's accomplished while additional facts can be found on the Naval Research page.

1969-12-31

311

Science Explorations  

NSDL National Science Digital Library

Science Explorations, a collaboration between AMNH and Scholastic, is designed to promote science literacy among students in grades 3 through 10. Each of the six online investigation brings the expertise and latest scientific discoveries of the Museum's world-class scientists to classrooms across the country. The investigations are:Animals, Adaptation, and the Galápagos Islands; Classify Insects; Journey Into Space; Investigate the Giant Squid; Soar with Bats; and Uncover Lizards and Snakes.

312

Science Bag  

NSDL National Science Digital Library

The "Science Bag" program was begun in 1973 by faculty members at the University of Wisconsin - Milwaukee. The group believed strongly that science should be more accessible to the general public. Since its inception, 150,000 people have attended the popular Friday night "Science Bag" programs presented by biologists, geologists, mathematicians, anthropologists, meteorologists, chemists, and physicists.~~~~Selected videos from this highly successful public series -- on Atmospheric Science, Biological Science, Chemistry, Geological Science, and Physics -- are now available online. Among the featured programs: "Chaos and Fractal Forms: Irregularity in Nature," "Alien Invaders: Exotic Species in the Food Web of the Great Lakes," and "Ancient Arrowheads, Roman Baseball Cards, and Optical Fibers: The Many Uses of Glass."~~~~The streaming programs (Adobe Flash format) are 45-70 minutes in length and are available in high and low speed formats.~~~~Visitors to the site may search the programs by Department, Professor, or Keyword.~~

Lasca, Norman

2009-07-08

313

Dynamics of highly excited nitroaromatics.  

PubMed

Although the photodissociation of nitroaromatics in low excitation electronic states has been extensively studied in recent decades, little is known about the highly excited electronic states. The fragmentation dynamics of three nitroaromatics, nitrobenzene, o-nitrotoluene, and m-nitrotoluene, in highly excited states, populated by the absorption of two photons at 271 nm, are studied with time-of-flight mass spectrometry. The temporal evolutions of the highly excited states are monitored by one-photon ionization at 408 nm. The transients of parent and fragment ions exhibit two ultrafast deactivation processes. The first process is ultrafast internal conversion from the initial excitation to Rydberg states in tens of femtoseconds. The second one is conversion from the Rydberg states to the vibrational manifold in the ground electronic states within hundreds of femtoseconds. The internal conversion process is accelerated by methyl substitution. In o-nitrotoluene, the two processes become much faster due to the hydrogen transfer from the CH(3) to the NO(2) group (ortho effect). PMID:21090786

Wang, Bingxing; Liu, Benkang; Wang, Yanqiu; Wang, Li

2010-12-23

314

Science Fiction on Film.  

ERIC Educational Resources Information Center

Reviews science fiction films used in a science fiction class. Discusses feature films, short science fiction films, short story adaptations, original science fiction pieces and factual science films that enrich literature. (EL)

Burmester, David

1985-01-01

315

Safer Science: Overloading Science Labs  

NSDL National Science Digital Library

The current recession has brought about a wave of changes for all of us. In some school districts, boards of education are "renegotiating" areas of teachers' contracts, including class size maximums. Science laboratories that have typically accommodated a

Roy, Ken

2009-07-01

316

The Science of Science Writing  

NSDL National Science Digital Library

This is an excellent article about the need for clear writing in the sciences. It also looks at specific language problems and suggests ways to avoid them. The entire article may be read in full text on the website.

Gopen, George; Swan, Judith

2012-11-06

317

Science Sampler: Science reading journals  

NSDL National Science Digital Library

Make homework more meaningful and deepen your students understanding of content material by using this effective strategy. Students construct Science Reading Journals that can be used throughout the entire school year and can easily accommodate student's with special needs.

Roy, Ken; Northrop, Laura

2005-03-01

318

Science Fiction Aids Science Teaching.  

ERIC Educational Resources Information Center

Cited are the experiences of the authors with a college-level course which used science fiction films to teach scientific principles. Included is a set of sample scientific concepts explored using the film "Forbidden Planet." (CW)

Dubeck, Leroy W.; And Others

1990-01-01

319

Excitation optimization for damage detection  

SciTech Connect

A technique is developed to answer the important question: 'Given limited system response measurements and ever-present physical limits on the level of excitation, what excitation should be provided to a system to make damage most detectable?' Specifically, a method is presented for optimizing excitations that maximize the sensitivity of output measurements to perturbations in damage-related parameters estimated with an extended Kalman filter. This optimization is carried out in a computationally efficient manner using adjoint-based optimization and causes the innovations term in the extended Kalman filter to be larger in the presence of estimation errors, which leads to a better estimate of the damage-related parameters in question. The technique is demonstrated numerically on a nonlinear 2 DOF system, where a significant improvement in the damage-related parameter estimation is observed.

Bement, Matthew T [Los Alamos National Laboratory; Bewley, Thomas R [UCSD

2009-01-01

320

Autoresonant Excitation of Antiproton Plasmas  

NASA Astrophysics Data System (ADS)

We will present results of the first longitudinal autoresonant excitation of a thermal antiproton plasma. We apply a swept-frequency drive field to an antiproton plasma in an anharmonic potential to resonantly control the longitudinal energy of the particles in the potential. We observe autoresonant excitation of the plasma as a macroparticle in the regime of cold, dense plasmas, while warmer, tenuous plasmas are not excited completely (as predicted by theory [1]). This technique has been used for initiating the formation of antihydrogen, as it provides a flexible method for injecting antiprotons into a positron plasma of fluctuating space-charge while minimizing the kinetic energy of the antiprotons possessed by the antiprotons just after injection. As efforts to trap and conduct spectroscopy on antihydrogen require the formation of cold antihydrogen, minimizing energy mismatches in formation is key to successful trapping. References [1] Barth, I., et al, Phys. Rev. Lett. 103, 155001 (2009)

Bertsche, William

2010-11-01

321

Modeling excitable systems: Reentrant tachycardia  

NASA Astrophysics Data System (ADS)

Excitable membranes are an important type of nonlinear dynamical system, and their study can be used to provide a connection between physical and biological circuits. We discuss two models of excitable membranes important in cardiac and neural tissues. One model is based on the Fitzhugh-Nagumo equations, and the other is based on a three-transistor excitable circuit. We construct a circuit that simulates reentrant tachycardia and its treatment by surgical ablation. This project is appropriate for advanced undergraduates as a laboratory capstone project or as a senior thesis or honors project and can also be a collaborative project, with one student responsible for the computational predictions and another for the circuit construction and measurements.

Lancaster, Jarrett L.; Hellen, Edward H.; Leise, Esther M.

2010-01-01

322

Science, computational science, and computer science: at a crossroads  

Microsoft Academic Search

We describe computational science as an interdisciplinary approach to doing science on computers. Our purpose is to introduce computational science as a legitimate interest of computer scientists.We present a possible foundation for computational science. These foundations show that there is a need to consider computational aspects of science at the scientific level. We next present some obstacles to computer scientists'

D. E. Stevenson

1993-01-01

323

Science Buddies: Careers in Science  

NSDL National Science Digital Library

This web page lets students browse more than 100 science and engineering careers to discover what scientists really do and what it takes to prepare for these careers. Each career profile provides basic information such as salary, job outlook, nature of the work, and degree requirements. Also included are videos featuring interviews with real scientists or on-the-job profiles. The Science Buddies website aims to promote deep understanding of scientific research in the K-12 classroom and through informal education.

2013-09-18

324

Biological Science Initative- Forensic Science  

NSDL National Science Digital Library

This website provides middle and high school teachers and students with concepts and techniques of forensic evidence analysis commonly employed in forensic laboratories. This site contains a series of laboratory exercises that can be downloaded for use in middle and high school settings. Experiments are designed to teach students basic principles and methods of forensic science and to motivate the teaching of science in the classroom. Experiments are designed to teach laboratory and data-collection techniques.

2011-06-09

325

Autoresonant Excitation of Antiproton Plasmas  

SciTech Connect

We demonstrate controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense, and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm plasma can be similarly excited. Antihydrogen was produced and trapped by using this technique to drive antiprotons into a positron plasma, thereby initiating atomic recombination.

Andresen, G. B.; Bowe, P. D.; Hangst, J. S. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Ashkezari, M. D.; Hayden, M. E. [Department of Physics, Simon Fraser University, Burnaby British Columbia, V5A 1S6 (Canada); Baquero-Ruiz, M.; Chapman, S.; Fajans, J.; Povilus, A.; So, C. [Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300 (United States); Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Madsen, N.; Werf, D. P. van der [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); Carpenter, P. T.; Hurt, J. L.; Robicheaux, F. [Department of Physics, Auburn University, Auburn, Alabama 36849-5311 (United States); Cesar, C. L. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil)

2011-01-14

326

Electron impact excitation of coronene  

NASA Technical Reports Server (NTRS)

A preliminary study of the electron-impact excitation of thermally evaporated coronene at 550 C was carried out using electron-energy-loss spectroscopy. Measurements of the energy-loss spectra of coronene at high (100 eV) and low (5-20 eV) impact energies are presented. One of the high-energy spectra was converted to an apparent generalized oscillator strength spectrum and compared to the photoabsorption spectrum of coronene. Observations concerning vibrational excitation of coronene by electron impact are also presented and discussed.

Khakoo, M. A.; Ratliff, J. M.; Trajmar, S.

1990-01-01

327

Nuclear excitation by positron annihilation  

SciTech Connect

Experimental and theoretical studies of the excitation of low-lying states of the nuclei /sup 113//sup ,//sup 115/In, /sup 111/Cd, /sup 103/Rh, /sup 107//sup ,//sup 109/Ag, /sup 176/Lu, and /sup 197/Au by the annihilation of positrons with atomic shell electrons are reviewed. Neutron emission from the /sup 9/ Be nucleus due to nonradiative annihilation of positrons is considered. A new phenomenon: excitation of the daughter nucleus by positron annihilation in ..beta../sup +/ decay: is discussed.

Vishnevskii, I.N.; Zheltonozhskii, V.A.; Kolomiets, V.M.

1988-03-01

328

Transverse excitations in liquid Sn.  

PubMed

Transverse acoustic (TA) excitation modes were observed in inelastic x-ray scattering (IXS) spectra of liquid Sn. The excitation energies and widths of the TA modes are in good agreement with results of an ab initio molecular dynamics simulation. By comparing current correlation spectra between the experimental and theoretical results quantitatively, we have concluded that the TA modes can be detected experimentally through the quasi-TA branches in the longitudinal current correlation spectra. The lifetime and propagation length of the TA modes were determined to be ~0.7 ps and 0.8-1.0 nm, respectively, corresponding to the size of cages formed instantaneously in liquid Sn. PMID:23378432

Hosokawa, S; Munejiri, S; Inui, M; Kajihara, Y; Pilgrim, W-C; Ohmasa, Y; Tsutsui, S; Baron, A Q R; Shimojo, F; Hoshino, K

2013-03-20

329

Observation of doubly excited levels in lithiumlike and beryliumlike titanium  

NASA Astrophysics Data System (ADS)

The satellite spectrum of heliumlike titanium has been studied using the Lawrence Livermore National Laboratory electron beam ion trap, EBIT II and a high resolution Bragg crystal spectrometer in von Hámos geometry. We initially ionize the titanium atoms to the heliumlike charge state, and then select an electron beam energy that overlaps the excitation energy for the KLM series of resonances. This allows us to populate doubly excited levels in lithiumlike TiXX as well as beryliumlike TiXIX by dielectronic remombination. We observe spectra of x-ray photons emitted at 90^rc to the electron beam. We have also calculated the photon energies, excitation energies, and resonance strengths of these resonances using an MCDF theory, and we find good agreement between the theoretical and experimental results. We gratefully acknwoledge support by the U. S. Office of Basic Energy Science, Chemical Sciences Division, and the LLNL Research Collaborations Program for HBCU's. This work was performed under the auspices of U. S. Department of Energy by Morehouse under contract No. DE-FG02-98ER14877, and by LLNL under contract No. W-7405-ENG-48.

Smith, A. J.; Beiersdorfer, P.; Harris, C. L.; Wong, K.; Chen, M.

2002-10-01

330

Science Bulletins  

NSDL National Science Digital Library

This Website brings current science to the general public, informal learning centers, and classrooms. The three Science Bulletins -- Astro, Earth, and Bio - present ongoing research and recent discoveries in astrophysics, Earth science, and biodiversity. Each bulletin has three types of stories: features, data visualizations, and weekly news snapshots. The Astro Bulletins weekly update includes a sequence of current images of the Sun provided by NASA. The video and editorial crew follows scientists into the field to capture original video material and interview scientists about their work-in-progress for the feature stories, which are presented as high-definition videos for informal learning centers and as rich-media collections on the Web. Data visualizations, presented in high-resolution for informal learning centers and in interactive formats on the Web, are based on satellite data sets from NASA, NOAA, and other sources for Earth and Bio; while AstroViz draws from the Museum's Digital Universe project, a growing three-dimensional map/database of celestial objects which has been developed with NASA support to enable science visualizations for research and education purposes. A free Educator's guide and learning activities tailored to the changing content are provided for the Science Bulletins web site.

331

Cool Science  

NSDL National Science Digital Library

Science is quite cool, but you don't need to tell this to the dedicated team at the Howard Hughes Medical Institute. Their website, Cool Science, entertains questions of all kinds, encourages young scientists to "get their hands dirty", and also provides educators with a range of resources, including interactive media features, lesson plans, and lab exercises. These materials are contained with six primary sections: "For Educators", "Biointeractive", "For Curious Kids", and "Ask A Scientist". Educators of all stripes can use the "For Educators" area to focus in on resources organized by type, topic, grade level, and also to sign up for the resources RSS feed. Moving on, the "Biointeractive" area features archived video lectures, virtual labs, and another series of animations on stem cells, cancer, and immunology. There's a great deal to explore here, and it's a site that anyone with an interest in science will want to share with others.

332

Theory & Science  

NSDL National Science Digital Library

Theory & Science is a "peer reviewed, academic journal that is devoted to the discussion of theory, science, and social change." Affiliated with the International Consortium for Alternative Academic Publication (ICAAP), Theory & Science is offered free of charge. The first issue, published fall of 2000, contains five feature articles, including "Towards An Understanding Of The Global Market System: A New Perspective For Economics," by Rolf Schroeder, and "The Place Of Theory In Applied Sociology: A Reflection," by Jay Weinstein, among others. The current call for papers reflects the editor's respect for intellectual creativity (independent of academic rank of the thinker), and invites participation from "anyone with a truly inspired thought, regardless of scientific disciple."

2005-11-01

333

Capacitive Excitation for Induction Generators  

Microsoft Academic Search

Up to the present, applications of induction generators have been limited, mainly because they must be paralleled with an existing synchronous system to determine their frequency and voltage and to obtain their necessary excitation. The tests described in this paper show that an induction machine may be operated as an independent or isolated generator at a predetermined voltage and frequency,

E. D. Bassett; F. M. Potter

1935-01-01

334

Magnetically induced pulser laser excitation  

Microsoft Academic Search

A novel excitation scheme has been developed for excimer discharge lasers. The technique uses pulse transformer technology to induce a fast, high voltage pulse directly onto a ground potential laser electrode resulting in the breakdown of the laser gas mix. Saturation of the pulse transformer core inductance then permits efficient energy transfer from the main energy storage circuit into the

R. S. Taylor; K. E. Leopold

1985-01-01

335

Dissociation of Highly Excited Molecules  

NASA Astrophysics Data System (ADS)

A survey of the spectroscopy and dynamics of the dissociation of highly excited molecules is presented with emphasis on superexcited molecules by electron- and photon-impact.(See review articles: a) Y. Hatano, The Physics of Electronic and Atomic Collisions, eds., L. J. Dube et al., AIP Press, New York (1995) pp.67-88; b) N.Kouchi et al., J. Phys. B, 30, 2319 (1997); c) Y. Hatano, Dynamics of Excited Molecules, ed., K. Kuchitsu, Elsevier, Amsterdam (1994) Chapter 6.) Topics will include newly developed experimental methods covering two-dimensional spectroscopy of photodissociation(M. Ukai et al., Phys. Rev. Lett., 74, 239 (1995).) (S. Machida et al., J. Phys. Chem. A. 101, 656 (1997).) (A. Ehresmann et al., J. Phys. B, 29, 3629 (1996).), and coincident electron-energy-loss spectroscopy of the dissociation dynamics of highly excited molecules.(T. Odagiri et al., J. Phys. B, 28, L465 (1995).)(T. Odagiri et al., J. Phys. B, 29, 1829 (1996).) The measurement of absolute photoionization quantum yields will also be discussed.(K. Kameta et al., J. Chem. Phys., 99, 2487 (1993).) Comparative studies of electron- and photon-impact dissociative excitation of molecules will be summarized. The molecules studied are H_2, N_2, O_2, CO, CO_2, N_2O, hydrocarbons, and some Si-containing compounds.

Hatano, Yoshihiko

1997-10-01

336

Elementary Excitations in Quantum Liquids.  

ERIC Educational Resources Information Center

Discusses elementary excitations and their role in condensed matter physics, focusing on quantum plasma, helium liquids, and superconductors. Considers research primarily conducted in the 1950s and concludes with a brief survey of some closely related further developments. (Author/JN)

Pines, David

1981-01-01

337

Pseudorandom selective excitation in NMR  

NASA Astrophysics Data System (ADS)

In this work, average Hamiltonian theory is used to study selective excitation under a series of small flip-angle ?-pulses ? ? {?}/{3} applied either periodically [corresponding to the DANTE pulse sequence] or aperiodically to a spin-1/2 system. First, an average Hamiltonian description of the DANTE pulse sequence is developed that is valid for frequencies either at or very far from integer multiples of {1}/{?}, where ? is the interpulse delay. For aperiodic excitation, a single resonance, ?sel, can be selectively excited if the ?-pulse phases are modulated in concert with the interpulse delays. The conditions where average Hamiltonian theory can be accurately applied to describe the dynamics under aperiodic selective pulses, which are referred to as pseudorandom-DANTE or p-DANTE sequences, are similar to those found for the DANTE sequence. Signal averaging over different p-DANTE sequences improves the apparent selectivity at ?sel by reducing the excitations at other frequencies. Experimental demonstrations of p-DANTE sequences and comparisons with the theory are presented.

Walls, Jamie D.; Coomes, Alexandra

2011-09-01

338

Climate Science  

NSDL National Science Digital Library

This unit was created for a specific population of middle school students in a small school for students with emotional disorders. The intention was to teach science standards and to re-teach related science concepts that were not mastered in elementary school, while preparing students to have a conversation about climate change using scientific information. With the seven principles of climate literacy in mind, seven lessons taking multiple class periods were designed to allow students to explore what climate is, how it is studied, how it changes through natural and man-made processes, how it affects humans, and what they can do to influence future climate.

2012-01-01

339

Rough Science  

NSDL National Science Digital Library

This PBS website supplements the TV series "Rough Science," where "five scientists are challenged to put their collective scientific knowledge to practical use." The scientists travel to the Mediterranean, Carriacou, New Zealand, and Death Valley. For each adventure, the website offers a series of challenges such as generating electricity, making soap, making paper and pen, and developing a metal detector. Along with learning how the participants became involved with science, students can read diary entries of their adventures. The Web Challenge offered in Series 2 is a fun way to learn about magnetism and electricity.

340

Hamburger Science  

NSDL National Science Digital Library

To teach students about food safety practices, the U.S. Food and Drug Administration (FDA) and the National Science Teachers Association (NSTA) formed a partnership to develop a free curriculum kit titled Science and Our Food Supply (FDA and NSTA 2001). Of the many lab activities in the program, the one most anticipated by students is "the hamburger lab" (FDA and NSTA 2001, 60). Students use a controlled experiment to fry meat, swab for bacteria, and incubate agar plates to determine bacteria-safe cooking temperatures.

Trent, Ann

2004-10-01

341

Slapshot Science!  

NSDL National Science Digital Library

The following resource is fromLessonopoly, which has created student activities and lesson plans to support the video series, Science of the Olympic Winter Games, created by NBC Learn and the National Science Foundation. Featuring exclusive footage from NBC Sports and contributions from Olympic athletes and NSF scientists, the series will help teach your students valuable scientific concepts. In this particular lesson, students will learn about the slapshot, which is the fastest, hardest shot in ice hockey. Students will investigate elastic collisions, energy transfer and momentum exchange and will conduct an experiment which simulates making a slapshot.

2010-01-01

342

Science Safety  

NSDL National Science Digital Library

Created by specialists at the Baylor College of Medicine's BioEd Online team, the Science Safety site brings together videos, pamphlets, and other instructional resources designed to help students and educators learn about lab safety. The site contains three key videos: "Tools and Equipment of Science," "Using a Bright Field Light Microscope," and "Using a Micropipettor." Demonstrators include scientists and teachers from around Texas and the tone of the films is erudite, age-appropriate, and accessible. Additionally, the site includes links to Lesson Demonstrations, which address subjects such as ecology, forces and motion, and microorganisms.

Vu, Michael

343

Ocean Science  

NSDL National Science Digital Library

The European Geosciences Union has been working on a number of open access journals over the past few years, and Ocean Science is just such an endeavor. The intent of the journal is to publish research articles, review papers, and short communications of all stripes. Visitors can sign up for RSS feeds, look over the "General Information" area, and also learn about their submission guidelines. In the "Online Library OS" area, visitors can view recently revised papers, complete issues, special issues, and also search past works by title or author. Also, visitors are welcome to comment on published works and they can also sign up to receive an email subscription to Ocean Science.

344

Science Curriculum Framework. Revised.  

ERIC Educational Resources Information Center

This document presents the revised Arkansas Science Curriculum Framework (1999), which replaces the Science Curriculum Framework of 1994. Three strands--physical science systems, life science systems, and Earth science/space science systems--were identified using an integrated approach to provide guidance in the science curriculum. A glossary and…

Arkansas State Dept. of Education, Little Rock.

345

The Science For Our Schools (SFOS) Program  

NASA Astrophysics Data System (ADS)

The Science For Our Schools (SFOS) program at California State University at Los Angeles places graduate students from Astronomy, Biology, Chemistry, Geology, and Physics with science teachers in secondary classrooms throughout the Los Angeles area. The program implements activities and demonstrations based on California's new science content standards. Graduate Fellows act as science communicators to bring the excitement of scientific research to high school classrooms. Fellows are partnered with highly experienced science teachers in seven different middle and high schools, most of which have high minority enrollment and large numbers of students from low-income families. In addition to curriculum development, our Fellows plan field trips, scout funding opportunities, facilitate lab equipment purchases, and help organize special events such as science fairs and "Ask a Scientist" nights. SFOS Fellows and PI's meet weekly to exchange ideas and experiences, to review current science education literature, and to preview curriculum developed for our middle and high school science classrooms. All SFOS participants gather at quarterly workshops to share the results of program activities through presentations and discussions. We thank the National Science Foundation for funding through the GK-12 program.

Terebey, S.; Mayo, D.; Strauss, J.

2004-12-01

346

Science and Religion in Science Fiction  

NSDL National Science Digital Library

These lectures will consider science fiction as a popular cultural context for informal science education (or miseducation) and the exploration of ethical and religious issues .It includes lectures by Dr Krauss on Science, non-science, and Nonsense in Science fiction, and Dr Russell on ET vs. GOD. ; Smack down, and also includes a discussion on both talks

;

2007-06-15

347

Discovering indigenous science: Implications for science education  

Microsoft Academic Search

Indigenous science relates to both the science knowledge of long-resident, usually oral culture peoples, as well as the science knowledge of all peoples who as participants in culture are affected by the worldview and relativist interests of their home communities. This article explores aspects of multicultural science and pedagogy and describes a rich and well-documented branch of indigenous science known

Gloria Snively; John Corsiglia

2001-01-01

348

National Science Foundation programs in computer science  

Microsoft Academic Search

This panel will discuss the various programs of the National Science Foundation dealing with Computer Science Education and Research. These include programs on basic research in computer science, research in computer science education and various programs designed to increase the quality of science education, especially where computers can plan a significant role in the educational process.

Bruce H. Barnes; Andrew R. Molnar; Lawrence H. Oliver; Robert F. Watson

1976-01-01

349

Science Notes.  

ERIC Educational Resources Information Center

Describes activities, games, experiments, demonstrations, and computer-oriented exercises in all science areas. Topics include energy flow through a marine ecosystem, using 2,4-dichlorophenoxyethanoic acid to demonstrate translocation in plants, use of the dichotomous key, use of leaf yeasts to monitor atmospheric pollution, and others. (JN)

School Science Review, 1986

1986-01-01

350

Kaleidoscope Science.  

ERIC Educational Resources Information Center

Presents a collection of science activities that have elementary students investigate how color can trick the eye and the brain. The activities involve working with contrasting colors, creating a rainbow, and exploring the connection between colors and words. An instructor reproducible features two color activities. (SM)

Janes, Patricia

2002-01-01

351

Science Notes.  

ERIC Educational Resources Information Center

Provides a reading list for A- and S-level biology. Contains several experiments and demonstrations with topics on: the intestine, bullock corneal cells, valences, the science of tea, automated hydrolysis, electronics characteristics, bromine diffusion, enthalpy of vaporization determination, thermometers, pendulums, hovercraft, Bernoulli fluid…

Shaw, G. W.; And Others

1989-01-01

352

Literary Science.  

ERIC Educational Resources Information Center

Explains the use of literacy in science education. Uses "Silent Spring", a book on environmental issues, to encourage students to think about the role of water in balancing the earth's system and possible actions against environmental concerns. Creates an environment for students to discuss their knowledge on the use of the pesticide DDT. (YDS)

Garrison, Megan R.

2000-01-01

353

Space Sciences  

NSDL National Science Digital Library

Space Sciences contains information on the solar system, the Sun, Moon, and formation of the Earth as well as a wallpaper gallery of astronomical images. There are links to real-time astronomical data, a virtual tour of the International Space Station, star charts, the NASA space launch schedule, maps of the night sky, satellite data, an Earth and Moon viewer, and more.

354

Innovation Science  

Microsoft Academic Search

The term innovation resonates broadly in the cyberspace, books, and journals. A careful analysis of the literature indicates that the knowledge of the underlying science of innovation is limited. Innovation in any domain can be enhanced by principles and insights from different disciplines. However, the process of identifying the linkages between the diverse disciplines and the target domain is not

Andrew Kusiak

2006-01-01

355

Reproducible Science?  

PubMed Central

The reproducibility of an experimental result is a fundamental assumption in science. Yet, results that are merely confirmatory of previous findings are given low priority and can be difficult to publish. Furthermore, the complex and chaotic nature of biological systems imposes limitations on the replicability of scientific experiments. This essay explores the importance and limits of reproducibility in scientific manuscripts.

Casadevall, Arturo; Fang, Ferric C.

2010-01-01

356

Science Notes.  

ERIC Educational Resources Information Center

Describes 26 different activities, experiments, demonstrations, and computer simulations in various topics in science. Includes instructional activities dealing with mural ecology, surface area/volume ratios, energy transfer in ecosystems, electrochemical simulations, alternating and direct current, terminal velocity, measuring the size of the…

School Science Review, 1986

1986-01-01

357

Science Cafe  

NSDL National Science Digital Library

More and more, research institutes and specialized centers of learning are turning to the world of podcasts, vodcasts, and other such multimedia devices to reach out to people from Peoria to Patagonia. The University of California, San Francisco recently opened up their own virtual science cafÃÂé, and this website represents an attempt to provide lively and interesting conversations about the "story of science." As a statement on their website remarks, "From stem cells and what sells to great ideas, yeasty trends and budding controversies, we will be developing a menu for your mind." They have delivered on this intriguing promise quite well, as visitors to the site will quickly discover. With close to a dozen talks online so far, visitors can learn about the mysteries of aging from researcher Cynthia Kenyon and how the world of basic science research differs in the United States as compared with Germany. One can imagine that this program could be used as a nice complement in science education courses for both high school and college.

358

Science Nation  

NSDL National Science Digital Library

An online magazine examining the breakthroughs and the possibilities for new discoveries about our planet, our universe and ourselves. Each week, Science Nation takes a dynamic, entertaining look at the research--and the researchers-- that will change our lives. The articles include text and video.

359

Boundless Science  

NASA Astrophysics Data System (ADS)

Our science is critical to understanding the future prospects for life. The laboratory for natural sciences encompasses our planet and reaches into the solar system. The forces of nature respect no boundaries. But, we who try to understand these forces are handicapped by national, political, language, religious, and other concocted barriers. These barriers limit both our effectiveness as scientists and our ability to reach those outside our community who need to know what we have uncovered about our environment. An unencumbered worldwide scientific community has been an objective with limited successes for too long. Action began in earnest after the first world war with the formation of the various scientific Unions and ICSU. Fifty years later Keith Runcorn initiated another approach, when he proposed what quickly became EGS and which has grown and evolved with the merger with EUG. To be truly effective we need to communicate and share comfortably with colleagues worldwide. Personal relationships and trust are required. We count on a high level of ethical behavior within our community. We individually must also be constantly vigilant for the encroachment of the manmade barriers that have held back science through time immemorial. Our scientific organizations cannot achieve this alone. They will facilitate, however, the onus is on each of us to reach out and form interlocking informal communities, which will bring our whole planet-wide community together at many overlapping levels. When we achieve this community, our science will more bountiful and better address the needs of human society.

Spilhaus, F.

2009-04-01

360

Skeptical Science.  

ERIC Educational Resources Information Center

Discusses the legitimacy of teaching about astrology, extrasensory perception, UFOs, touch therapy, cloning dinosaurs, or any other unusual claims in the classroom. Suggests that bringing unusual claims to the science classroom is an opportunity to motivate students in the principles of scientific thought. (SAH)

Scott, Alan J.; Barnhart, Carolyn M.; Parejko, Ken S.; Schultz, Forrest S.; Schultz, Steven E.

2001-01-01

361

Science Buddies  

NSDL National Science Digital Library

Awarded a prestigious prize in 2011 for online resources in education by Science magazine, the Science Buddies website helps both students and scientists by "build[ing] a remarkable bridge between inquisitive students who want access to current research and scientists who want to conduct outreach for their own projects." Visitors interested in science fair activities and guidance should definitely check out the Project Ideas and Project Guide tabs located near the top of the page. There are over 1,000 Project Ideas, including "Which Flour Has the Greatest Glob of Gluten?" and "Hey, There's Corn in my Candy!" (both found in the Cooking and Food subcategory). Those persons with an interest in engineering will appreciate the "Engineering Design Project Guide" that can be found under the Project Guide tab. This guide walks students through an engineering project, from Gathering Data to Generating Ideas to Implementing a Solution. Finally, there is also an Advanced Project Guide for students and teachers involved in high school science competitions.

2012-03-23

362

Animal Science.  

ERIC Educational Resources Information Center

Presents a set of hands-on, outdoor science experiments designed to teach elementary school students about animal adaptation. The experiments focus on: how color camouflage affects an insect population; how spiderlings find a home; and how chameleons camouflage themselves by changing color. (SM)

VanCleave, Janice

2001-01-01

363

Science Opportunities with LSST  

NASA Astrophysics Data System (ADS)

The Large Synoptic Survey Telescope [?rb|http://www.lsst.org|] will provide the community with a leap in wide field survey capability. The LSST will be a community resource, with broad access to the data and no proprietary data withholding period. We encourage the community to think about how they might exploit the LSST data, and in particular how frequent multi-band imaging to 24.5 AB magnitude per 15 sec could enable innovative new science. The 8.4-meter telescope and 3 billion pixel camera covering ten square degrees will be sky noise limited in less than 10 seconds in each of 6 optical bands (ugrizy). This wide-fast-deep capability is enabled by advances in microelectronics, software, and large optics fabrication. The LSST system will have three main components: the telescope and optics, the wide field imager, and the system software. Significant developments have taken place in all three areas, as highlighted in the companion posters. Final site selection will occur this Spring. First light is scheduled for 2012, science operations for 2013. Our observing simulations show ˜ 2000 exposures per each 10 square degree field, with total 20,000 square degree sky coverage and a 10-year survey. Key science drivers all utilize the same data and are representative of LSST's system capabilities: Precision Characterization of Dark Energy Mapping the Milky Way Taking an Inventory of the Solar System Exploring the Transient Optical Sky In addition to enabling all four of these major scientific initiatives, LSST will make it possible to pursue many other research programs. The community has suggested a number of exciting programs using these data, and the long-lived data archives of the LSST will have the astrometric and photometric precision needed to support entirely new research directions which will inevitably develop during the next several decades. The LSST will produce the largest non-proprietary data set in the world.

Tyson, J. A.; Ivezic, Z.; Kahn, S.; Strauss, M.; Stubbs, C.; Sweeney, D.; LSST Collaboration

2005-12-01

364

Science Sampler: School yard geology  

NSDL National Science Digital Library

"Can we break rocks again today?" This statement is typical of the excitement students show for identifying rock types after they apply their rock identification knowledge to the geology in the school yard. Many school yards, although bulldozed during construction, still exhibit telling outcrops of the underlying bedrock. Armed with a few materials, you can discover what is just outside your door while modeling the joy of doing science. This activity fits into the curriculum after the rock cycle and igneous, sedimentary, and metamorphic rock identification labs.

Hagberg, Beverly; Sterling, Donna R.

2008-12-01

365

Entropy Driven Atomic Motion in Laser-Excited Bismuth  

SciTech Connect

We introduce a thermodynamical model based on the two-temperature approach in order to fully understand the dynamics of the coherent A{sub 1g} phonon in laser-excited bismuth. Using this model, we simulate the time evolution of (111) Bragg peak intensities measured by Fritz et al.[Science 315, 633 (2007)] in femtosecond x-ray diffraction experiments performed on a bismuth film for different laser fluences. The agreement between theoretical and experimental results is striking not only because we use fluences very close to the experimental ones but also because most of the model parameters are obtained from ab initio calculations performed for different electron temperatures.

Giret, Y.; Gelle, A.; Arnaud, B. [Institut de Physique de Rennes (IPR), UMR UR1-CNRS 6251, Campus de Beaulieu-Bat 11 A, 35042 Rennes Cedex, France, EU (France)

2011-04-15

366

Raman excitation profile of diphenylamine  

NASA Astrophysics Data System (ADS)

Vibrational analyses have been done on the basis of Raman and FTIR spectra of diphenylamine (DPA) and contributions of the two rings to different normal modes of vibration have been discussed. From the analyses of Raman excitation profiles (REPs) of several vibrational modes, useful information about the geometries of the molecule in different excited states have been obtained. Also vibronic coupling has been found to be important in the case of some Raman bands. Besides an interesting Molecular Orbital (MO) calculation, exploring the structure of DPA in the allowed singlet electronic state ( 1La) , has been presented. Moreover, possible orientations of the two rings with respect to the amine nitrogen atom in the ground and in the 1La states have been discussed.

Sett, P.; De, A. K.; Chattopadhyay, S.; Mallick, P. K.

2002-02-01

367

Excitation spectrum of a supersolid.  

PubMed

Conclusive experimental evidence of a supersolid phase in any known condensed matter system is presently lacking. On the other hand, a supersolid phase has been recently predicted for a system of spinless bosons in continuous space, interacting via a broad class of soft-core, repulsive potentials. Such an interaction can be engineered in assemblies of ultracold atoms, providing a well-defined pathway to the unambiguous observation of this fascinating phase of matter. In this Letter, we study by first principles computer simulations the elementary excitation spectrum of the supersolid, and show that it features two distinct modes, namely, a solidlike phonon and a softer collective excitation, related to broken translation and gauge symmetry, respectively. PMID:22680879

Saccani, S; Moroni, S; Boninsegni, M

2012-04-27

368

Forensic science – A true science?  

Microsoft Academic Search

While the US jurisprudence of the 1993 Daubert hearing requires judges to question not only the methodology behind, but also the principles governing, a body of knowledge to qualify it as scientific, can forensic science, based on Locard's and Kirk's Principles, pretend to this higher status in the courtroom? Moving away from the disputable American legal debate, this historical and

Frank Crispino; Olivier Ribaux; Max Houck; Pierre Margot

2011-01-01

369

The Science in Science Fiction.  

ERIC Educational Resources Information Center

This 12-chapter book discusses the scientific facts behind the ideas included in the novels of Robert Heinlein, Isaac Asimov, Frederik Pohl, Arthur C. Clark and other science fiction writers. Areas explored in the first 11 chapters include: exploration of deep space; energy and exotic power sources; likelihood of extra-terrestrial life and the…

Nicholls, Peter, Ed.

370

Heliophysics Science  

NASA Astrophysics Data System (ADS)

HELIOPHYSICS SUMMER SCHOOLS: NASA Living With a Star and the University Corporation for Atmospheric Research, Visiting Scientist Programs sponsor the Heliophysics Summer Schools to build this new field of science. The series of summer schools, started in 2007, help graduate students and scientists learn and develop the science of heliophysics as a broad, coherent discipline that reaches in space from the Earth's troposphere to the depths of the Sun, and in time from the formation of the solar system to the distant future. The first three years of the school will result in three textbooks for use at universities worldwide. Subsequent years will both teach other generations of students and develop the complementary materials that support teaching of heliophysics at both graduate and undergraduate levels. Heliophysics is a developing scientific discipline integrating studies of the Sun’s variability, the surrounding heliosphere, and climatic environments. Over the past few centuries, our understanding of how the Sun drives space weather and climate on the Earth and other planets has advanced at an ever-increasing rate. The first textbook, (Heliophysics I Plasma Physics of the Local Cosmos, edited by Carolus J. Schrijver, Lockheed Martin and George L. Siscoe, Boston University) integrates such diverse topics for the first time as a coherent intellectual discipline. It emphasizes the physical processes coupling the Sun and Earth, allowing insights into the interaction of the solar wind and radiation with the Earth’s magnetic field, atmosphere and climate system. It provides a core resource for advanced undergraduates and graduates, and also constitutes a foundational reference for researchers in heliophysics, astrophysics, plasma physics, space physics, solar physics, aeronomy, space weather, planetary science and climate science. HELIOPHYSICS POSTDOCTORAL PROGRAM: Hosts and applicants are invited to apply to a new postdoctoral fellowship program designed to train the next generation of researchers in the emerging field of Heliophysics. Two major topics of focus for LWS are the science of space weather and of the Sun-climate connection. Preference will be given to applicants whose proposed research addresses one of these two foci; but any research program relevant to LWS will be considered. Since the goal of this fellowship program is to train Sun-Earth system researchers, preference will also be given to research projects that cross the traditional Heliophysics subdomains of the Sun, heliosphere, magnetosphere, and ionosphere/upper atmosphere, as well as Sun-climate investigations. Host institutions and mentoring scientists will play critical roles. Hosts may post information about their research on a central database for this program: www.vsp.ucar.edu/HeliophysicsScience.

Austin, M.; Schrjver, K.; Siscoe, G. L.; Bhattacharjee, A.; Longcope, D. W.; Sojka, J. J.; Guhathakurta, M.

2009-12-01

371

Communicating Science  

NASA Astrophysics Data System (ADS)

We are in an era of rapidly changing communication media, which is driving a major evolution in the modes of communicating science. In the past, a mainstay of scientific communication in popular media was through science “translators”; science journalists and presenters. These have now nearly disappeared and are being replaced by widespread dissemination through, e.g., the internet, blogs, YouTube and journalists who often have little scientific background and sharp deadlines. Thus, scientists are required to assume increasing responsibility for translating their scientific findings and calibrating their communications to non-technical audiences, a task for which they are often ill prepared, especially when it comes to controversial societal issues such as tobacco, evolution, and most recently climate change (Oreskes and Conway 2010). Such issues have been politicized and hi-jacked by ideological belief systems to such an extent that constructive dialogue is often impossible. Many scientists are excellent communicators, to their peers. But this requires careful attention to detail and logical explanation, open acknowledgement of uncertainties, and dispassionate delivery. These qualities become liabilities when communicating to a non-scientific audience where entertainment, attention grabbing, 15 second sound bites, and self assuredness reign (e.g. Olson 2009). Here we report on a program initiated by NCAR and UCAR to develop new approaches to science communication and to equip present and future scientists with the requisite skills. If we start from a sound scientific finding with general scientific consensus, such as the warming of the planet by greenhouse gases, then the primary emphasis moves from the “science” to the “art” of communication. The art cannot have free reign, however, as there remains a strong requirement for objectivity, honesty, consistency, and above all a resistance to advocating particular policy positions. Targeting audience attitudes and beliefs, which studies such as the Six Americas research help identify, is key to effective science communications (e.g. Leiserowitz, Maibach, et al, 2009). We argue that the impact of the scientific message can be substantially improved by targeting it to these additional factors. This does require an understanding of the audience and a repackaging of the message to different societal groups. Logical and dispassionate presentation of evidence works for a target scientific audience, but major decisions from the policy to the personal level are influenced by many factors including immediacy, economics, culture, community leaders, emotional framing, and ideological filters.

Holland, G. J.; McCaffrey, M. S.; Kiehl, J. T.; Schmidt, C.

2010-12-01

372

Intruder excitations in P35  

NASA Astrophysics Data System (ADS)

The structure of the neutron-rich N=20 nucleus P35 has been investigated through nucleon transfer experiments using the 208Pb(36,X?) reaction at 230 MeV. The level structure, of mainly 1?? excitations in P35, has been significantly expanded. The measurements are compared with shell model calculations. Experimental branching ratio limits are reported for predicted transitions to the 2?? bandheads in P35 and Si34.

Wiedeking, M.; Rodriguez-Vieitez, E.; Fallon, P.; Carpenter, M. P.; Clark, R. M.; Cline, D.; Cromaz, M.; Descovich, M.; Janssens, R. V. F.; Lee, I.-Y.; Deleplanque, M.-A.; Macchiavelli, A. O.; Stephens, F. S.; Teng, R.; Wang, X.; Ward, D.; Wu, C. Y.; Zhu, S.; Otsuka, T.; Utsuno, Y.; Volya, A.

2008-09-01

373

Magnetic excitations in vanadium spinels  

Microsoft Academic Search

We study magnetic excitations in vanadium spinel oxides AV2O4 (A=Zn,Mg,Cd) using two models: the first one is a superexchange model for vanadium S=1 spins and the second one includes, in addition, spin-orbit coupling and crystal anisotropy. We show that the experimentally observed magnetic ordering can be obtained in both models; however, the orbital ordering is different with and without spin-orbit

N. B. Perkins; O. Sikora

2007-01-01

374

Chiral multiplets of excited mesons  

Microsoft Academic Search

It is shown that experimental meson states with spins J=0,1,2,3 in the energy range 1.9–2.4 GeV obtained in a recent partial wave analysis of proton–antiproton annihilation at LEAR remarkably confirm all predictions of chiral symmetry restoration. Classification of excited q?q mesons according to the representations of chiral U(2)L×U(2)R group is performed. There are two important predictions of chiral symmetry restoration

L. Ya. Glozman

2004-01-01

375

Self-excited multifractal dynamics  

NASA Astrophysics Data System (ADS)

We introduce the self-excited multifractal (SEMF) model, defined such that the amplitudes of the increments of the process are expressed as exponentials of a long memory of past increments. The principal novel feature of the model lies in the self-excitation mechanism combined with exponential nonlinearity, i.e. the explicit dependence of future values of the process on past ones. The self-excitation captures the microscopic origin of the emergent endogenous self-organization properties, such as the energy cascade in turbulent flows, the triggering of aftershocks by previous earthquakes and the "reflexive" interactions of financial markets. The SEMF process has all the standard stylized facts found in financial time series, which are robust to the specification of the parameters and the shape of the memory kernel: multifractality, heavy tails of the distribution of increments with intermediate asymptotics, zero correlation of the signed increments and long-range correlation of the squared increments, the asymmetry (called "leverage" effect) of the correlation between increments and absolute value of the increments and statistical asymmetry under time reversal.

Filimonov, V.; Sornette, D.

2011-05-01

376

Learning Nuclear Science with Marbles  

NASA Astrophysics Data System (ADS)

Nuclei are small: if an atom was the size of a football field, the nucleus would be an apple sitting on the 50-yd line. At the same time, nuclei are dense: the Earth, compressed to nuclear density, could fit inside four Sears Towers. The subatomic level is strange and exotic. For that reason, it's not hard to get young minds excited about nuclear science. But how does one move beyond analogies like those above and offer a better understanding of the extraordinary world of the nucleus? This is the challenge faced by the outreach program at Michigan State University's National Superconducting Cyclotron Laboratory (NSCL), a National Science Foundation-supported facility specializing in the creation and study of rare isotopes. It was necessary to devise a model of the nucleus that students could interact with and even use to approximate the nuclear reactions that create exotic nuclei. The solution was to use magnetic marbles.

Constan, Zach

2010-02-01

377

Entropy Driven Atomic Motion in Laser-Excited Bismuth  

NASA Astrophysics Data System (ADS)

We introduce a thermodynamical model based on the two-temperature approach in order to fully understand the dynamics of the coherent A1g phonon in laser-excited bismuth. Using this model, we simulate the time evolution of (111) Bragg peak intensities measured by Fritz et al. [Science 315, 633 (2007)SCIEAS0036-807510.1126/science.1135009] in femtosecond x-ray diffraction experiments performed on a bismuth film for different laser fluences. The agreement between theoretical and experimental results is striking not only because we use fluences very close to the experimental ones but also because most of the model parameters are obtained from ab initio calculations performed for different electron temperatures.

Giret, Y.; Gellé, A.; Arnaud, B.

2011-04-01

378

Planning a Science Fair  

ERIC Educational Resources Information Center

Presented are views, on planning science fairs and science fair projects, of a fair coordinator, a science teacher, and students. Also included are 25 questions which might result in science fair projects. (SL)

Ebert, Jim

1976-01-01

379

Science.org  

NSDL National Science Digital Library

Science.org is a purely informational resource which promotes the advancement of knowledge in various scientific fields and science education. Come to Science.org for the latest science news and information.

380

Blade Vibration Due to Different Flow Excitation.  

National Technical Information Service (NTIS)

Results of experiments carried out at various excitation conditions, variations in geometry, and especially in diffuser flow conditions are presented. The analysis includes the study of blade resonance excitation, blade flutter, vibrations due to surge, a...

U. Haupt

1987-01-01

381

Reactions of Electronically Excited Oxygen Molecules.  

National Technical Information Service (NTIS)

A method of obtaining measurable concentrations of excited oxygen for kinetic studies has been developed, and a number of reactions of these excited molecules are described. Evidence is presented for simultaneous electronic transitions in a weakly bound c...

L. W. Bader E. A. Ogryzlo

1964-01-01

382

Computer sciences  

NASA Technical Reports Server (NTRS)

The Computer Science Program provides advanced concepts, techniques, system architectures, algorithms, and software for both space and aeronautics information sciences and computer systems. The overall goal is to provide the technical foundation within NASA for the advancement of computing technology in aerospace applications. The research program is improving the state of knowledge of fundamental aerospace computing principles and advancing computing technology in space applications such as software engineering and information extraction from data collected by scientific instruments in space. The program includes the development of special algorithms and techniques to exploit the computing power provided by high performance parallel processors and special purpose architectures. Research is being conducted in the fundamentals of data base logic and improvement techniques for producing reliable computing systems.

Smith, Paul H.

1988-01-01

383

Science Matters  

NSDL National Science Digital Library

The Environmental Protection Agency (EPA) publishes the "Science Matters" newsletter to inform the general public about its research and advocacy activities on behalf of the American public. The newsletter was first published in 2010, and is a terrific source of information on everything from green chemistry to renewable energy. In the About this Issue area, visitors can learn about the topical focus of each issue. In the Science Features, visitors can read articles such as "Nanomaterials: Harnessing the Potential, Understanding the Risks" and "Partnerships for a Safer Chemical Future." Users shouldn't miss the Ask a Scientist feature, which profiles a different EPA scientist in each issue. The In the News area brings together updates about new partnerships with colleges, universities, and international collaborators. [KMG

2013-03-14

384

Science Junction  

NSDL National Science Digital Library

North Carolina State University has made available the Science Junction website. The goal of this website is to create an interaction between the researchers and educators at North Carolina State University and the teachers, children, and parents of North Carolina. In addition, the website aims to provide a center for teaching as well as learning and integrating science into people's daily lives. Sections provided at the website are: Data Depot, Student Station, and Teacher Terminal, among others. In the Game Room section, within the Student Station, users can "try their hand at hitting a space vehicle through a special track in space" in the game Space Track. This offers users a fun way to learn more about Newton's Laws while testing their skills and knowledge in physics. Although the website has been launched, some sections are still under construction.

385

Highlighting Your Science to NASA  

NASA Astrophysics Data System (ADS)

An effort is underway to provide greater visibility within NASA headquarters, and to those who provide funding to NASA, of the outstanding work that is being performed by scientists involved in the Solar System Exploration Research and Analysis Programs, most of whom are DPS members. In support of this effort, a new feature has been developed for the NASA Headquarters Solar System Exploration Division web site whereby researchers can provide a synopsis of their current research results. The site (http://solarsystem.nasa.gov/spotlight/ - Username: your email address Password: sse) is an online submission area where NASA-funded scientists can upload the results of their research. There they provide their contact information, briefly describe their research, and upload any associated images or graphics. The information is available to a limited number of reviewers and writers at JPL. Each month, one researcher's work will be chosen as a science spotlight. After a writer interviews the scientist, a brief Power Point presentation that encapsulates their work will be given to Dr. Colleen Hartman at NASA headquarters. She will then present the exciting findings to Associate Administrator for Space Science, Dr. Ed Weiler. The information from some of these highlights can serve as a basis to bring Principal Investigators to NASA Headquarters for exposure to media through Space Science Updates on NASA television. In addition, the science results may also be incorporated into briefing material for the Office of Management and Budget and congressional staffers. Some spotlights will also be converted into feature stories for the Solar System Exploration website so the public, too, can learn about exciting new research. The site, http://solarsystem.nasa.gov/, is one of NASA's most visited. Over the past decade, there has been a trend of flat budgets for Research and Analysis activities. By giving more visibility to results of Solar System research, our goal is to encourage higher program funding levels from Congress and demonstrate the relevance of NASA research to the American public in general.

Sharkey, C.

2003-12-01

386

Science Connects  

NSDL National Science Digital Library

Science Connects has been chosen to run the STEMNET program for the West of Scotland, and their work will be of great interest to science educators. The STEM ambassador program is what distinguishes the STEMNET program from other STEM programs. The UK-wide program works with "volunteers from a wide range of disciplines, such as forensic science, geology, mechanical engineering, parasitology...etc. who want to share their enthusiasm for their careers to encourage pupils to take an interest in STEM Subjects." The "Case Studies" tab on the left side of any page offers visitors a look at what some ambassadors have done with their field of study. Visitors should check out case study #4, about one Dr. Linda Thomson, who teaches young kids about chemistry and forensics. Visitors will also want to check out case study #9, about Alistair McNeil, who happens to be a health, safety and environment manager who recommends a career in construction. All told, the site is well worth a visit for those interested in promoting STEM education.

387

Two-photon excitation of aluminium phthalocyanines  

SciTech Connect

A demonstration is given of the feasibility of two-photon excitation of aluminium phthalocyanine and of the pharmaceutical preparation 'Fotosens', used in photodynamic therapy. The excitation source was an Nd:YAG laser emitting at the 1064 nm wavelength. The spectra of the two-photon-excited luminescence were obtained and the two-photon absorption cross sections were determined. (lasers in medicine)

Meshalkin, Yu P; Alfimov, E E; Makukha, V K [Novosibirsk State Technical University, Novosibirsk (Russian Federation); Vasil'ev, N E; Denisov, A N; Ogirenko, A P [Siberian Laser Medicine Centre, Novosibirsk (Russian Federation)

1999-12-31

388

Steam turbine generator excitation system modernization  

Microsoft Academic Search

Many power plants built 20-30 years ago are facing problems associated with the excitation system used for controlling generator output voltage. After years of reliable operation, generation is experiencing increased down time due to maintenance associated with the existing excitation equipment. Reliability of the excitation system has become an issue, especially where many of these generation plants may be critical

Richard C. Schaefer

1995-01-01

389

Collective Excitations in the Theory of Superconductivity  

Microsoft Academic Search

The complex dielectric constant of a superconductor and the Meissner effect are derived in a manner which is gauge invariant, from the theory of superconductivity due to Bardeen, Cooper, and Schrieffer. The collective excitations are important in maintaining gauge invariance; the longitudinal collective excitations ensure that a static vector potential produces no longitudinal current and the transverse collective excitations contribute

G. Rickayzen

1959-01-01

390

Blog - Team Science Toolkit  

Cancer.gov

The Team Science Toolkit is a dynamic, interactive website to support team science and the Science of Team Science (SciTS) field. The Toolkit provides resources for investigators who are using team science approaches, as well as scholars and evaluators who are studying or evaluating the processes and outcomes of team science.

391

Promoting Engineering Careers Using Modern Sensors in High School Science Labs  

Microsoft Academic Search

A student’s first introduction to engineering and technology is typically through high school science. Unfortunately, science\\u000a labs often make use of antiquated tools that fail to deliver exciting lab content. As a result, many students are turned off\\u000a by science, fail to excel on standardized science exams, and do not consider engineering as a career.\\u000a \\u000a This paper reports on the

Edwin Yu; Magued Iskander; Vikram Kapila; Noel Kriftcher

392

Exciting Times Call for Collaboration  

ERIC Educational Resources Information Center

Brain science already has much to contribute to education and will become even more important in the future. Brain research is not going away; it is increasing and will continue to do so. As such, educators need better tools to deal with it. In this article, the author argues that educators desperately need new understandings, new ways to think…

Jensen, Eric P.

2008-01-01

393

Materials Science  

NASA Technical Reports Server (NTRS)

The Materials Science Program is structured so that NASA s headquarters is responsible for the program content and selection, through the Enterprise Scientist, and MSFC provides for implementation of ground and flight programs with a Discipline Scientist and Discipline Manager. The Discipline Working Group of eminent scientists from outside of NASA acts in an advisory capacity and writes the Discipline Document from which the NRA content is derived. The program is reviewed approximately every three years by groups such as the Committee on Microgravity Research, the National Materials Advisory Board, and the OBPR Maximization and Prioritization (ReMaP) Task Force. The flight program has had as many as twenty-six principal investigators (PIs) in flight or flight definition stage, with the numbers of PIs in the future dependent on the results of the ReMaP Task Force and internal reviews. Each project has a NASA-appointed Project Scientist, considered a half-time job, who assists the PI in understanding and preparing for internal reviews such as the Science Concept Review and Requirements Definition Review. The Project Scientist also insures that the PI gets the maximum science support from MSFC, represents the PI to the MSFC community, and collaborates with the Project Manager to insure the project is well-supported and remains vital. Currently available flight equipment includes the Materials Science Research Rack (MSRR-1) and Microgravity Science Glovebox. Ground based projects fall into one or more of several categories. Intellectual Underpinning of Flight Program projects include theoretical studies backed by modeling and computer simulations; bring to maturity new research, often by young researchers, and may include preliminary short duration low gravity experiments in the KC-135 aircraft or drop tube; enable characterization of data sets from previous flights; and provide thermophysical property determinations to aid PIs. Radiation Shielding and preliminary In Situ Resource Utilization (ISRU) studies work towards future long duration missions. Biomaterials support materials issues affecting crew health. Nanostructured Materials are currently considered to be maturing new research, and Advanced Materials for Space Transportation has as yet no PIs. PIs are assigned a NASA Technical Monitor to maintain contact, a position considered to be a 5 percent per PI effort. Currently 33 PIs are supported on the 1996 NRA, which is about to expire, and 59 on the 1998 NRA. Two new NRAs, one for Radiation Shielding and one for Materials Science for Advanced Space Propulsion are due to be announced by the 2003 fiscal year. MSFC has a number of facilities supporting materials science. These include the Microgravity Development Laboratory/SD43; Electrostatic Levitator Facility; SCN Purification Facility; Electron Microscope/Microprobe Facility; Static and Rotating Magnetic Field Facility; X-Ray Diffraction Facility; and the Furnace Development Laboratory.

2003-01-01

394

Studying Team Science - Team Science Toolkit  

Cancer.gov

The science of team science (SciTS) is a rapidly emerging field focused on understanding and enhancing the processes and outcomes of team science. A key goal of SciTS is to learn more about factors that maximize the efficiency, productivity, and effectiveness of team science initiatives.

395

Contextualized Science for Teaching Science and Technology.  

ERIC Educational Resources Information Center

A comprehensive view of science and technology in curricular reforms and materials is needed to promote public understanding and participation in science issues. This paper presents the results of an analysis of the treatment of the nature of science and technology in science curricular materials in India. Textbook sections on the conceptions of…

Koul, Ravinder

396

Towards a Science of Science Teaching  

ERIC Educational Resources Information Center

This article is a contribution to the search for evidence-based models of learning to improve science education. The author believes that modern teachers should look to the sciences of cognitive psychology and neuroscience to build a science of science teaching. Understanding the relationships between learning and the brain's structure and…

Yates, Carolyn

2009-01-01

397

Big Science and Big Big Science  

ERIC Educational Resources Information Center

In his introduction to the science shows feature in "Primary Science" 115, Ian B. Dunne asks the question "Why have science shows?" He lists a host of very sound reasons, starting with because "science is fun" so why not engage and entertain, inspire, grab attention and encourage them to learn? He goes onto to state that: "Even in today's…

Marshall, Steve

2012-01-01

398

Laser-based excitation and diagnostics of planar fractures  

NASA Astrophysics Data System (ADS)

Faults are of interest not only to earth science, but also at different scales in the non-destructive testing (NDT) community. Remote sensing of faults is of interest to both communities, with the idea of inverting for the fracture properties in a non-invasive way. Alternatively, the wave field directly excited at the fracture is of interest to both communities because the waves thus radiated are equivalent to those emitted by acoustic emissions or micro-earthquakes. Much can be learned from recording of elastic waves excited at the the fracture. Based on technology developed for NDT, we use laser ultrasonics in the laboratory to excite and detect elastic waves, in order to determine the properties of fractures or faults in laboratory rock and synthetic samples. We show examples of wave propagation in a clear Poly(methyl methacrylate) cylinder. By focusing a high power infrared (IR) laser inside the cylinder we create a visible single disk-shaped fracture near the center of the sample. The laser generates a short pulse (~20 ns) of infrared light that is absorbed by the sample material at the focal point and is converted into heat. The sudden thermal expansion generates stress and forms a fracture parallel to the cylindrical axis. We excite elastic waves at the surface of the sample using the same high-power pulsed laser, but at a much lower energy setting, and with an unfocused beam. We measure the direct and scattered wave field from the fracture with a laser interferometer, and also excite the fracture directly with a fraction of the source laser energy impinging directly on the fracture. A comparison of the direct excitation and the elastic scattered wavefields, including studies of the tip diffractions from the fracture, shows strong agreement. The measured tip diffractions carry information about the stress concentration near the crack tips, which is crucial for understanding rupture processes. This novel laboratory technique allows us to measure the source radiation pattern under various conditions, and opens new possibilities for understanding earthquake dynamics and fracture dynamics, as a function of stress loads, local excitation of the fracture, and fluid content of fractures.

Blum, T. E.; Van Wijk, K.; Snieder, R.; Willis, M. E.

2011-12-01

399

Science@NASA: Direct to People!  

NASA Technical Reports Server (NTRS)

Science@NASA is a science communication effort sponsored by NASA's Marshall Space Flight Center. It is the result of a four year research project between Marshall, the University of Florida College of Journalism and Communications and the internet communications company, Bishop Web Works. The goals of Science@NASA are to inform, inspire, and involve people in the excitement of NASA science by bringing that science directly to them. We stress not only the reporting of the facts of a particular topic, but also the context and importance of the research. Science@NASA involves several levels of activity from academic communications research to production of content for 6 websites, in an integrated process involving all phases of production. A Science Communications Roundtable Process is in place that includes scientists, managers, writers, editors, and Web technical experts. The close connection between the scientists and the writers/editors assures a high level of scientific accuracy in the finished products. The websites each have unique characters and are aimed at different audience segments: 1. http://science.nasa.gov. (SNG) Carries stories featuring various aspects of NASA science activity. The site carries 2 or 3 new stories each week in written and audio formats for science-attentive adults. 2. http://liftoff.msfc.nasa.gov. Features stories from SNG that are recast for a high school level audience. J-Track and J-Pass applets for tracking satellites are our most popular product. 3. http://kids. msfc.nasa.gov. This is the Nursemaids site and is aimed at a middle school audience. The NASAKids Club is a new feature at the site. 4. http://www.thursdaysclassroom.com . This site features lesson plans and classroom activities for educators centered around one of the science stories carried on SNG. 5. http://www.spaceweather.com. This site gives the status of solar activity and its interactions with the Earth's ionosphere and magnetosphere.

Koczor, Ronald J.; Adams, Mitzi; Gallagher, Dennis; Whitaker, Ann (Technical Monitor)

2002-01-01

400

Science kitsch and pop science: A reconnaissance.  

PubMed

Science kitsch? The combination of these two words rings like an oxymoron. Science - as the common saying has it - exposes, discovers, tells the truth; kitsch conceals, covers, lies. I think, this "shadow" of science deserves a specific scrutiny, not only because it reflects the altered place and role of science in contemporary "knowledge" society but also because it pinpoints the task of relocating science in the "multicultural" context of postmodernism, with its different epistemic claims. The genre of science kitsch may help to regain credit by working as a probe to detect false pretensions, explanatory exuberance and exaggerations in science. PMID:23833170

Kaeser, Eduard

2013-07-01

401

California Academy of Sciences: Science Now  

NSDL National Science Digital Library

ScienceNOW is a regularly updated Web site from the California Academy of Sciences, which features a changing display of Academy research in the natural sciences. Four featured sections -- Headline Science, Academy Research, Where in the World, and Wild Lives -- offer brief overviews of discoveries by Academy scientists and other "headline-making" science news. Each section includes photos and figures, as well as links to related Web sites or news stories. In general, ScienceNOW offers a quick and agreeable way to keep up with Academy projects and news-making natural science research around the world.

402

Turbulent swirling jets with excitation  

NASA Technical Reports Server (NTRS)

An existing cold-jet facility at NASA Lewis Research Center was modified to produce swirling flows with controllable initial tangential velocity distribution. Two extreme swirl profiles, i.e., one with solid-body rotation and the other predominated by a free-vortex distribution, were produced at identical swirl number of 0.48. Mean centerline velocity decay characteristics of the solid-body rotation jet flow exhibited classical decay features of a swirling jet with S - 0.48 reported in the literature. However, the predominantly free-vortex distribution case was on the verge of vortex breakdown, a phenomenon associated with the rotating flows of significantly higher swirl numbers, i.e., S sub crit greater than or equal to 0.06. This remarkable result leads to the conclusion that the integrated swirl effect, reflected in the swirl number, is inadequate in describing the mean swirling jet behavior in the near field. The relative size (i.e., diameter) of the vortex core emerging from the nozzle and the corresponding tangential velocity distribution are also controlling factors. Excitability of swirling jets is also investigated by exciting a flow with a swirl number of 0.35 by plane acoustic waves at a constant sound pressure level and at various frequencies. It is observed that the cold swirling jet is excitable by plane waves, and that the instability waves grow about 50 percent less in peak r.m.s. amplitude and saturate further upstream compared to corresponding waves in a jet without swirl having the same axial mass flux. The preferred Strouhal number based on the mass-averaged axial velocity and nozzle exit diameter for both swirling and nonswirling flows is 0.4.

Taghavi, Rahmat; Farokhi, Saeed

1988-01-01

403

The Forum: The Soft Shoe and Hard Sell of Science Teaching  

ERIC Educational Resources Information Center

Dispels the notion that exciting and imaginative science is the result of packaged curriculum materials or teaching methods. Instead, the necessity to follow students' inclinations and desires rather than rigid study guides is advocated. (CP)

Twaronite, Eugene A.

1978-01-01

404

Doing Science with eLISA: Astrophysics and Cosmology in the Millihertz Regime.  

National Technical Information Service (NTIS)

This document introduces the exciting and fundamentally new science and astronomy that the European New Gravitational Wave Observatory (NGO) mission (derived from the previous LISA proposal) will deliver. The mission (which we will refer to by its informa...

A. Berti A. Bohe A. Klein A. Lobo A. Petiteau B. F. Schutz C. Caprini E. K. Porter G. Nelemans J. Gair J. F. Dufaux K. Danzmann M. Colpi M. Vallisneri N. J. Cornish O. Jennrich P. Binetruy P. Jetzer R. Stebbins R. N. Lang S. Aoudia S. Babak S. P. Amaro S. T. McWilliams T. Littenberg

2012-01-01

405

Using Food Science in Special Interest Groups  

NASA Astrophysics Data System (ADS)

Employment opportunities are excitingly broad and varied for food scientists. There are many special interest organizations including food trade associations, commodity promotion groups, and consumer advocacy organizations that require the skills of a food scientist. Unique aspects of these employers and jobs will be explained along with the special food science and related talents that contribute to success in these fields. I have had the good fortune of using my food science background working for a trade association in Washington, D.C. and I will use my own job as an example. After all, I work for a wonderful sector of the food industry—the candy industry.

Bodor, Alison

406

Sloshing motions in excited tanks  

NASA Astrophysics Data System (ADS)

A fully non-linear finite difference model has been developed based on inviscid flow equations. Numerical experiments of sloshing wave motion are undertaken in a 2-D tank which is moved both horizontally and vertically. Results of liquid sloshing induced by harmonic base excitations are presented for small to steep non-breaking waves. The simulations are limited to a single water depth above the critical depth corresponding to a tank aspect ratio of hs/ b=0.5. The numerical model is valid for any water depth except for small depth when viscous effects would become important. Solutions are limited to steep non-overturning waves. Good agreement for small horizontal forcing amplitude is achieved between the numerical model and second order small perturbation theory. For large horizontal forcing, non-linear effects are captured by the third-order single modal solution and the fully non-linear numerical model. The agreement is in general good, both amplitude and phase. As expected, the third-order compared to the second-order solution is more accurate. This is especially true for resonance, high forcing frequency and mode interaction cases. However, it was found that multimodal approximate forms should be used for the cases in which detuning effects occur due to mode interaction. We present some test cases where detuning effects are evident both for single dominant modes and mode interaction cases. Furthermore, for very steep waves, just before the waves overturn, and for large forcing frequency, a discrepancy in amplitude and phase occurs between the approximate forms and the numerical model. The effects of the simultaneous vertical and horizontal excitations in comparison with the pure horizontal motion and pure vertical motion is examined. It is shown that vertical excitation causes the instability associated with parametric resonance of the combined motion for a certain set of frequencies and amplitudes of the vertical motion while the horizontal motion is related to classical resonance. It is also found that, in addition to the resonant frequency of the pure horizontal excitation, an infinite number of additional resonance frequencies exist due to the combined motion of the tank. The dependence of the non-linear behaviour of the solution on the wave steepness is discussed. It is found that for the present problem, non-linear effects become important when the steepness reaches about 0.1, in agreement with the physical experiments of Abramson [Rep. SP 106, NASA, 1966].

Frandsen, Jannette B.

2004-05-01

407

Collective excitations in the continuum  

SciTech Connect

Pairing (particle-particle) giant resonances are analyzed within a shell-model formalism in the complex energy plane with the aim of understanding why they have not been observed so far. A comparison is made with the equivalent particle-hole mode by applying the formalism to the analysis of the well-understood particle-hole giant resonance. It is found that because of the proper treatment of the continuum intrinsic to the formalism, giant pairing resonances lie much higher than previously predicted and that some of them may be too wide to be observed, whereas others are meaningful excitations. For these, new experimental searches are proposed.

Dussel, G. G. [Departamento de Fisica, FCEyN-UBA, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Betan, R. Id [Departamento de Quimica y Fisica, FCEIA (UNR)-Instituto de Fisica Rosario, IFIR (CONICET), 2000 Rosario (Argentina); Liotta, R. J. [KTH, Alba Nova University Center, S-10691 Stockholm (Sweden); Vertse, T. [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen (Hungary); Faculty of Informatics, University of Debrecen, H-4010 Debrecen (Hungary)

2009-12-15

408

High Frequency Chandler Wobble Excitation  

NASA Astrophysics Data System (ADS)

Variations of Earth rotation on sub-daily to secular timescales are caused by mass redistributions in the Earth system as a consequence of geophysical processes and gravitational influences. Forced oscillations of polar motion are superposed by free oscillations of the Earth, i.e. the Chandler wobble and the free core nutation. In order to study the interactions between externally induced polar motion and the Earth's free oscillations, a non-linear gyroscopic model has been developed. In most of the former investigations on polar motion, the Chandler wobble is introduced as a damped oscillation with predetermined frequency and amplitude. However, as the effect of rotational deformation is a backcoupling mechanism of polar motion on the Earth's rotational dynamics, both period and amplitude of the Chandler wobble are time-dependent when regarding additional excitations from, e.g., atmospheric or oceanic mass redistributions. The gyroscopic model is free of any explicit information concerning amplitude, phase, and period of free oscillations. The characteristics of the Earth's free oscillation is reproduced by the model from rheological and geometrical parameters and rotational deformation is taken into account. This enables to study the time variable Chandler oscillation when the gyro is forced with atmospheric and oceanic angular momentum from the global atmospheric ECHAM3-T21 general circulation model together with the ocean model for circulation and tides OMCT driven by ECHAM including surface pressure. Besides, mass redistributions in the Earth's body due to gravitational and loading deformations are regarded and external torques exerted by Moon and Sun are considered. The numerical results of the gyro are significantly related with the geodetically observed time series of polar motion published by the IERS. It is shown that the consistent excitation is capable to counteract the damping and thus to maintain the Chandler amplitude. Spectral analyses of the ECHAM and OMCT forcing fields give no hint for increased excitation power in the Chandler band. Thus it is assumed, that continuous high frequency excitation due to stochastic weather phenomena is responsible for the perpetuation of the Chandler wobble.

Seitz, F.; Stuck, J.; Thomas, M.

2003-04-01

409

Sports Science  

NSDL National Science Digital Library

This Exploratorium website provides creative educational materials for introductory physics students and teachers. Users can learn about the science behind a homerun, find out how the physics of balance helps enthusiasts surf the waves, and discover the physics behind many other popular sports. The site is equipped with interviews, enticing images, and enthralling descriptions. Visitors can find interesting articles covering sports topics such as fitness challenges for climbers and the way balls bounce. With these inventive tutorials, students are sure to become enthused about physics.

2007-12-12

410

Planetary Science  

NSDL National Science Digital Library

Astronomy notes is an educational resource for introductory astronomy classes for undergraduates. This section gives a extensive introduction to planetary science. Topics in this portion of the website include properties of planets, such as distance, mass, volume, density, and composition. There is also explanations on escape velocity, temperature, and gravity and how they affect planetary bodies. Other topics included are: the meanining of atmospheric colors, magnetic fields, the magnetic dynamo theory, seismology, differences between Mars, Earth, and Venus, and the properties of rings and moons in our solar system.

Strobel, Nick

2004-07-16

411

Science Conferences  

NSDL National Science Digital Library

Would you like to know what professional conferences are being held around the world at any specific time? AllConferences.net provides this free service. Over thirty science categories are represented and include everything from the 2002 Geological Society of America Annual meeting in Denver to the upcoming Environmental Flows for River Systems Conference & Fourth Ecohydraulics Symposium in Cape Town, South Africa. Each entry includes a description of the event, times, locations, contact information, and relevant links. Users can search or browse the events by category and even submit a conference of their own. Now all you need is funding for the trip.

2000-01-01

412

Pathfinders: Science  

NSDL National Science Digital Library

The Indianapolis Marion County Public Library provides these educational subject specific pathfinders "that contain a list of library materials, web sites, and other information about a topic." The Science section includes topics focused on how the human body works, including the circulatory, digestive, excretory, muscular, nervous, respiratory, and skeletal systems. Each topic includes a detailed diagram and facts about the body system, and a variety of helpful books and online resources appropriate for children. This site is a useful resource for gathering information on a specific subject or browsing a variety of topics.

413

Science Circus  

NASA Astrophysics Data System (ADS)

As a Smithsonian artist in residence Rhys Thomas taught basic Newtonian Physics using circus tricks. As an Oregon Museum of Science and Industry outreach performer he has used his juggling and equilibristic skills to demonstrate gyroscopics, gravity, inertia and other topics in 10 states and three countries. Rhys will share his insights and tips on "performing" rather than just "presenting" physics. He will perform some demos ala Ed Sullivan. He will also discuss how a basic understanding of physics has influenced his artistic expression in non-educational theatrical performances that earned him an Oregon Arts Fellowship in 2005. Sponsored by Stanley Micklavzina of the University of Oregon.

Thomas, Rhys D.

2006-12-01

414

NEWS: Science awareness  

NASA Astrophysics Data System (ADS)

The Particle Physics and Astronomy Research Council's award scheme in the public understanding of science and technology for 1999 is currently under way and the first closing date has already passed. The second date for the receipt of applications for the Small Awards scheme is 10 October (open to anyone), with awards ranging from £250 up to the maximum of £10 000 per project. The funding can be used for materials, salaries, travel and subsistence, and there may be a slight preference towards projects involving young people and schools. Subject areas must be those relevant to PPARC: particle physics; space, ionospheric, solar and planetary science; astronomy, astrophysics and cosmology. Application documentation can be obtained from PUST Office Room 2232, PPARC, Polaris House, North Star Avenue, Swindon SN2 1SZ (tel: 01793 442002, e-mail: pr_pus@pparc.ac.uk and website http://www.pparc.ac.uk/role/notes.html). And whilst on this same theme, the deadline is fast approaching for a new Institute of Physics scheme intended to recognize work on increasing awareness of the exciting nature of physics and its relevance and impact on everyday life. The Public Awareness of Physics awards will recognize individuals and groups who have demonstrated excellence, inspiration and innovation in bringing physics to the public and assist in raising the status of this kind of activity. There are no restrictions on eligibility and nominees do not have to be members of the Institute of Physics, physicists or physics trained. Nominations may be made by anyone, with up to five awards to be given annually. Further details, nomination guidelines and forms are available from Katie Perry, Public Affairs Department, Institute of Physics, 76 Portland Place, London W1N 3DN (tel: 0171 470 4800, e-mail: katie.perry@iop.org).

1999-05-01

415

Physical and Life Sciences 2008 Science & Technology Highlights.  

National Technical Information Service (NTIS)

This collage encapsulates the breadth of science disciplines in Physical and Life Sciences (PLS)--physics, chemistry, materials sciences, earth sciences, and life sciences. This broad range of science enables PLS to achieve its mission of creating and app...

A. U. Hazi D. L. Correll

2009-01-01

416

LSST Science Book, Version 2.0  

Microsoft Academic Search

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be

Paul A. Abell; Julius Allison; Scott F. Anderson; John R. Andrew; J. Roger P. Angel; Lee Armus; David Arnett; S. J. Asztalos; Tim S. Axelrod; Stephen Bailey; D. R. Ballantyne; Justin R. Bankert; Wayne A. Barkhouse; Jeffrey D. Barr; L. Felipe Barrientos; Aaron J. Barth; James G. Bartlett; Andrew C. Becker; Jacek Becla; Timothy C. Beers; Joseph P. Bernstein; Rahul Biswas; Michael R. Blanton; Joshua S. Bloom; John J. Bochanski; Pat Boeshaar; Kirk D. Borne; Marusa Bradac; W. N. Brandt; Carrie R. Bridge; Michael E. Brown; Robert J. Brunner; James S. Bullock; Adam J. Burgasser; James H. Burge; David L. Burke; Phillip A. Cargile; Srinivasan Chandrasekharan; George Chartas; Steven R. Chesley; You-Hua Chu; David Cinabro; Mark W. Claire; Charles F. Claver; Douglas Clowe; A. J. Connolly; Kem H. Cook; Jeff Cooke; Asantha Cooray; Kevin R. Covey; Christopher S. Culliton; Roelof de Jong; Willem H. de Vries; Victor P. Debattista; Francisco Delgado; Ian P. Dell'Antonio; Saurav Dhital; Rosanne Di Stefano; Mark Dickinson; Benjamin Dilday; S. G. Djorgovski; Gregory Dobler; Ciro Donalek; Gregory Dubois-Felsmann; Josef Durech; Ardis Eliasdottir; Michael Eracleous; Laurent Eyer; Emilio E. Falco; Xiaohui Fan; Christopher D. Fassnacht; Harry C. Ferguson; Yanga R. Fernandez; Brian D. Fields; Douglas Finkbeiner; Eduardo E. Figueroa; Derek B. Fox; Harold Francke; James S. Frank; Josh Frieman; Sebastien Fromenteau; Muhammad Furqan; Gaspar Galaz; A. Gal-Yam; Peter Garnavich; Eric Gawiser; John Geary; Perry Gee; Robert R. Gibson; Kirk Gilmore; Emily A. Grace; Richard F. Green; William J. Gressler; Carl J. Grillmair; Salman Habib; J. S. Haggerty; Mario Hamuy; Alan W. Harris; Suzanne L. Hawley; Alan F. Heavens; Leslie Hebb; Todd J. Henry; Edward Hileman; Eric J. Hilton; Keri Hoadley; J. B. Holberg; Matt J. Holman; Steve B. Howell; Leopoldo Infante; Zeljko Ivezic; Suzanne H. Jacoby; Bhuvnesh Jain; Jedicke; M. James Jee; J. Garrett Jernigan; Saurabh W. Jha; Kathryn V. Johnston; R. Lynne Jones; Mario Juric; Mikko Kaasalainen; Styliani; Kafka; Steven M. Kahn; Nathan A. Kaib; Jason Kalirai; Jeff Kantor; Mansi M. Kasliwal; Charles R. Keeton; Richard Kessler; Zoran Knezevic; Adam Kowalski; Victor L. Krabbendam; K. Simon Krughoff; Shrinivas Kulkarni; Stephen Kuhlman; Mark Lacy; Sebastien Lepine; Ming Liang; Amy Lien; Paulina Lira; Knox S. Long; Suzanne Lorenz; Jennifer M. Lotz; R. H. Lupton; Julie Lutz; Lucas M. Macri; Ashish A. Mahabal; Rachel Mandelbaum; Phil Marshall; Morgan May; Peregrine M. McGehee; Brian T. Meadows; Alan Meert; Andrea Milani; Christopher J. Miller; Michelle Miller; David Mills; Dante Minniti; David Monet; Anjum S. Mukadam; Ehud Nakar; Douglas R. Neill; Jeffrey A. Newman; Sergei Nikolaev; Martin Nordby; Paul O'Connor; Masamune Oguri; John Oliver; Scot S. Olivier; Julia K. Olsen; Knut Olsen; Edward W. Olszewski; Hakeem Oluseyi; Nelson D. Padilla; Alex Parker; Joshua Pepper; John R. Peterson; Catherine Petry; Philip A. Pinto; James L. Pizagno; Bogdan Popescu; Andrej Prsa; Veljko Radcka; M. Jordan Raddick; Andrew Rasmussen; Arne Rau; Jeonghee Rho; James E. Rhoads; Gordon T. Richards; Stephen T. Ridgway; Brant E. Robertson; Rok Roskar; Abhijit Saha; Ata Sarajedini; Evan Scannapieco; Terry Schalk; Rafe Schindler; Samuel Schmidt; Sarah Schmidt; Donald P. Schneider; German Schumacher; Ryan Scranton; Jacques Sebag; Lynn G. Seppala; Ohad Shemmer; Joshua D. Simon; M. Sivertz; Howard A. Smith; J. Allyn Smith; Nathan Smith; Anna H. Spitz; Adam Stanford; Keivan G. Stassun; Jay Strader; Michael A. Strauss; Christopher W. Stubbs; Donald W. Sweeney; Alex Szalay; Paula Szkody; Masahiro Takada; Paul Thorman; David E. Trilling; Virginia Trimble; Anthony Tyson; Richard Van Berg; Daniel Vanden Berk; Jake VanderPlas; Licia Verde; Bojan Vrsnak; Lucianne M. Walkowicz; Benjamin D. Wandelt; Sheng Wang; Yun Wang; Michael Warner; Risa H. Wechsler; Andrew A. West; Oliver Wiecha; Benjamin F. Williams; Beth Willman; David Wittman; Sidney C. Wolff; W. Michael Wood-Vasey; Przemek Wozniak; Patrick Young; Andrew Zentner; Hu Zhan

2009-01-01

417

AGU Public Affairs: How to Get Involved in Science Policy  

NASA Astrophysics Data System (ADS)

AGU Public Affairs offers many ways for its members to get involved in science policy at different levels of participation, whether you would love to spend a year working as a resident science expert in a congressional office in Washington, D.C., or would rather simply receive email alerts about Earth and space science policy news. How you can get involved: Sign up for AGU Science Policy Alerts to receive the most relevant Earth and space science policy information delivered to your email inbox. Participate in one of AGU's Congressional Visits Days to speak with your legislators about important science issues. Attend the next AGU Science Policy Conference in spring 2013. Participate in events happening on Capitol Hill, and watch video of past events. Learn about AGU Embassy Lectures, where countries come together to discuss important Earth and space science topics. Learn how you can comment on AGU Position Statements. Apply to be an AGU Congressional Science Fellow, where you can work in a congressional office for one year and serve as a resident science expert, or to be an AGU Public Affairs Intern, where you can work in the field of science policy for three months. The AGU Public Affairs Team will highlight ways members can be involved as well as provide information on how the team is working to shape policy and inform society about the excitement of AGU science.

Landau, E. A.; Hankin, E. R.; Uhlenbrock, K. M.

2012-12-01

418

How a Trip to the Freezer Can Help Children Learn Science  

ERIC Educational Resources Information Center

There are lots of exciting ways for children to learn science. Going on a journey is one of them. However, when going to distant places is not possible, a virtual journey may be the next best option. Ricky, one of the authors' puppets, helps children to make virtual journeys, and this can create an exciting context for them to raise questions and…

Keogh, Brenda; Naylor, Stuart

2011-01-01

419

Community Science @ Your Library  

ERIC Educational Resources Information Center

The National Science Foundation predicts that the United States will be unable to meet its future demand for scientists and engineers because student interest in science and math is waning. The goal of many community science programs is to increase the number of students majoring in science and to increase public science literacy.

Young, Terrence E., Jr.

2004-01-01

420

Super Science Connections  

NASA Astrophysics Data System (ADS)

The Super Science Connections workbook was developed by teachers, specifically for K-3 teachers. It contains relevant and fun hands-on activities centered around science concepts or science process skills. It smoothly integrates physical science and life science with other areas of the curriculum: math, health, social studies, art, writing, and children's literature.

McKean, Patricia B.

1999-07-01

421

Science for Real Life  

ERIC Educational Resources Information Center

State and national standards identify what students should know and be able to do, including what it means to "do" science, the historical significance of science achievement and its ethical underpinnings, and science from the human perspective. Middle level science programs that address the full range of science standards and connect learning to…

Hammerman, Elizabeth

2008-01-01

422

Science Fair Project Ideas  

NSDL National Science Digital Library

Science Buddies offers free science fair project ideas, answers, and tools for students and teachers in grades K-12. With a comprehensive offering of tools from the Topic Selection Wizard to the Teachers Guide to Science Projects, Science Buddies empowers teachers and students to explore science through hands on activities that are engaging and educational.

423

Science Education Notes.  

ERIC Educational Resources Information Center

Eight articles are included in this collection. Topics include: multicultural science, teaching science with metaphors, development of a graded assessment scheme in science, relative performance of boys and girls in chemistry, promoting science understanding, formative evaluations, science background of primary teachers, and promoting creativity…

Antonouris, George; And Others

1989-01-01

424

Skateboard Science  

NSDL National Science Digital Library

This new exhibit from the Exploratorium (last described in the February 19, 1999 Scout Report) lets users in on the techniques and equipment skateboarders use to seemingly bend the law of gravity. In the trickscience section, the site explains the physics behind the ollie, a fundamental jumping technique; mid-air maneuvers; and McTwists and Caballerials with illustrations, concise text, and several experiments to try at home. The equipment section offers an in-depth look at skateboard design and construction and how they have changed over time. In addition, the site also contains a glossary of skateboard terms and a RealPlayer G2 archive of a recent (June 12) webcast of a skateboard science exhibition at the Exploratorium.

425

Science: Podcast  

NSDL National Science Digital Library

Brown dwarfs, numerosity maps, and social learning in bird migration are but a few of the topics covered within these excellent podcasts offered up by Science magazine. The audio explorations here date back to 2005 and users can browse around at their leisure. Some of the recent offerings include conversations about North Korean volcanoes, faulty ribosomes, and how pesticides might be used to prevent suicides. Each podcast is between 44 and 47 minutes in length and visitors can read along with a complete transcript for each installment. Needless to say, the materials here can be utilized in the classroom or for the general edification of those wishing to know more about the natural world.

2013-09-13

426

The Vega Science Trust: Online Science Programmes  

NSDL National Science Digital Library

The nonprofit, UK-based Vega Science Trust broadcasts free science programs over the Internet. The programs "are mainly produced by experts in science and engineering and many have been previously shown on mainstream television." The Vega Science Trust website contains a sizeable collection of science programs for viewing. Program subject categories include: Biology, Health, Molecular Biology, Safety, Physics, and more. As indicated by the various categories, the programs address a wide range of issues including ocean life, genetically modified organisms, brain science, and ageing, to name a few. In addition to being categorized by subject, the annotated programs can also be browsed by scientist, by series, and by alphabetic order.

427

The Nature of Science and Science Inquiry  

NSDL National Science Digital Library

In a knowledge-centered science classroom, students work to answer scientifically oriented questions by creating explanations based on evidence. This approach, called science inquiry , is how science is conducted. It creates a learning environment that reflects the culture of science. The National Research Council (1996) states that "inquiry into authentic questions generated from student experiences is the central strategy for teaching science." This free selection describes what science inquiry is and how it should look in the classroom. It includes the Table of Contents, Introduction, and Index. As a special bonus, an inspiring poem and two inquiry-based articles designed for elementary and middle school students are also included.

Doug Ronsberg, There'S M.; Kaitlyn Hood And Jack A. Gerlovich, Inquiring M.; William Straits, A. L.

2008-01-01

428

State preparation and excited electronic and vibrational behavior in hemes.  

PubMed

The temporally overlapping, ultrafast electronic and vibrational dynamics of a model five-coordinate, high-spin heme in a nominally isotropic solvent environment has been studied for the first time with three complementary ultrafast techniques: transient absorption, time-resolved resonance Raman Stokes, and time-resolved resonance Raman anti-Stokes spectroscopies. Vibrational dynamics associated with an evolving ground-state species dominate the observations. Excitation into the blue side of the Soret band led to very rapid S2 --> S1 decay (sub-100 fs), followed by somewhat slower (800 fs) S1 --> S0 nonradiative decay. The initial vibrationally excited, non-Boltzmann S0 state was modeled as shifted to lower energy by 300 cm(-1) and broadened by 20%. On a approximately 10 ps time scale, the S0 state evolved into its room-temperature, thermal distribution S0 profile largely through VER. Anti-Stokes signals disappear very rapidly, indicating that the vibrational energy redistributes internally in about 1-3 ps from the initial accepting modes associated with S1 --> S0 internal conversion to the rest of the macrocycle. Comparisons of anti-Stokes mode intensities and lifetimes from TRARRS studies in which the initial excited state was prepared by ligand photolysis [Mizutani, T.; Kitagawa, T. Science 1997, 278, 443, and Chem. Rec. 2001, 1, 258] suggest that, while transient absorption studies appear to be relatively insensitive to initial preparation of the electronic excited state, the subsequent vibrational dynamics are not. Direct, time-resolved evaluation of vibrational lifetimes provides insight into fast internal conversion in hemes and the pathways of subsequent vibrational energy flow in the ground state. The overall similarity of the model heme electronic dynamics to those of biological systems may be a sign that the protein's influence upon the dynamics of the heme active site is rather subtle. PMID:17020382

Challa, J Reddy; Gunaratne, Tissa C; Simpson, M Cather

2006-10-12

429

Excited baryons in lattice QCD  

NASA Astrophysics Data System (ADS)

We present the first results for the masses of positive and negative parity excited baryons calculated in lattice QCD using an O(a2)-improved gluon action and a fat-link irrelevant clover (FLIC) fermion action in which only the irrelevant operators are constructed with APE-smeared links. The results are in agreement with earlier calculations of N* resonances using improved actions and exhibit a clear mass splitting between the nucleon and its chiral partner. A correlation matrix analysis reveals two low-lying JP=1/2- states with a small mass splitting. The study of different ? interpolating fields suggests a similar splitting between the lowest two ?1/2- octet states. However, the empirical mass suppression of the ?*(1405) is not evident in these quenched QCD simulations, suggesting a potentially important role for the meson cloud of the ?*(1405) and/or a need for more exotic interpolating fields.

Melnitchouk, W.; Bilson-Thompson, S.; Bonnet, F. D.; Hedditch, J. N.; Lee, F. X.; Leinweber, D. B.; Williams, A. G.; Zanotti, J. M.; Zhang, J. B.

2003-06-01

430

Supersymmetric approach to excited states.  

PubMed

We present here a supersymmetric (SUSY) approach for determining excitation energies within the context of a quantum Monte Carlo scheme. By using the fact that SUSY quantum mechanics gives rises to a series of isospectral Hamiltonians, we show that Monte Carlo ground-state calculations in the SUSY partners can be used to reconstruct accurately both the spectrum and states of an arbitrary Schrodinger equation. Since the ground state of each partner potential is nodeless, we avoid any "node" problem typically associated with the Monte Carlo technique. Although we provide an example of using this approach to determine the tunneling states in a double-well potential, the method is applicable to any 1D potential problem. We conclude by discussing the extension to higher dimensions. PMID:19919079

Bittner, Eric R; Maddox, Jeremy B; Kouri, Donald J

2009-12-31

431

Collective excitations of supersymmetric plasma  

SciTech Connect

Collective excitations of N=1 supersymmetric electromagnetic plasma are studied. Since the Keldysh-Schwinger approach is used, not only equilibrium but also nonequilibrium plasma, which is assumed to be ultrarelativistic, is under consideration. The dispersion equations of photon, photino, electron, and selectron modes are written down and the self-energies, which enter the equations, are computed in the hard loop approximation. The self-energies are discussed in the context of effective action which is also given. The photon modes and electron ones appear to be the same as in the usual ultrarelativistic plasma of electrons, positrons, and photons. The photino modes coincide with the electron ones and the selectron modes are as of a free relativistic massive particle.

Czajka, Alina [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Mrowczynski, Stanislaw [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Soltan Institute for Nuclear Studies, 00-681 Warsaw (Poland)

2011-02-15

432

Coulomb excitation of ruthenium isotopes  

NASA Astrophysics Data System (ADS)

The B(E2) values of the 89.4, 340.4, 575.5, 617.4 and 719.2 keV states of 99Ru and 127.2, 306.8, 422.0 and 544.9 keV states of 101Ru have been deduced by measuring the yields of gamma-rays following Coulomb excitation of a metallic ruthenium target with 3.0 MeV protons at Variable Energy Cyclotron, Chandigarh. The gamma-ray spectra were measured at 55° to the beam line using a 50 cm 3 Ge(Li) detector (resolution: 2.5 keV at 1332 keV). The present B(E2) values for different states in 99Ru and 101Ru are compared with the values available in the literature.

Arora, B. K.; Mehta, D.; Rani, Rakesh; Cheema, T. S.; Trehan, P. N.

1987-04-01

433

Deconfined fractionally charged excitation in any dimensions  

SciTech Connect

An exact incompressible quantum liquid is constructed at the filling factor 1/m{sup 2} in the square lattice. It supports deconfined fractionally charged excitation. At the filling factor 1/m{sup 2}, the excitation has fractional charge e/m{sup 2}, where e is the electric charge. This model can be easily generalized to the n-dimensional square lattice (integer lattice), where the charge of excitations becomes e/m{sup n}. -- Highlights: ? We demonstrate that the fractionally-charged excitations can in principle exist in any dimensions. ? We compute the fractional charge of the excitations (e{sup ?}=e/m{sup D}). ? We demonstrate that the fractionally-charged excitation is in a deconfined phase.

Chern, Chyh-Hong, E-mail: chchern@ntu.edu.tw; Huang, Po-Hao; Lee, Hong-Hsi

2013-05-15

434

Excitation of interstellar hydrogen chloride  

NASA Technical Reports Server (NTRS)

We have computed new rate coefficients for the collisional excitation of HCl by He, in the close-coupled formalism and using an interaction potential determined recently by Willey, Choong, & DeLucia. Results have been obtained for temperatures between 10 K and 300 K. With the use of the infinite order sudden approximation, we have derived approximate expressions of general applicability which may be used to estimate how the rate constant for a transition (J to J prime) is apportioned among the various hyperfine states F prime of the final state J prime. Using these new rate coefficients, we have obtained predictions for the HCl rotational line strengths expected from a dense clump of interstellar gas, as a function of the HCl fractional abundance. Over a wide range of HCl abundances, we have found that the line luminosities are proportional to abundance(exp 2/3), a general result which can be explained using a simple analytical approximation. Our model for the excitation of HCl within a dense molecular cloud core indicates that the J = 1 goes to 0 line strengths measured by Blake, Keene, & Phillips toward the Orion Molecular Cloud (OMC-1) imply a fractional abundance n(HCl)/n(H2) approximately 2 x 10(exp -9), a value which amounts to only approximately 0.3% of the cosmic abundance of chlorine nuclei. Given a fractional abundance of 2 x 10(exp -9), the contribution of HCl emission to the total radiative cooling of a dense clump is small. For Orion, we predict a flux approximately 10(exp -19) W/sq cm for the HCl J = 3 goes to 2 line near 159.8 micrometers, suggesting that the strength of this line could be measured using the Infrared Space Observatory.

Neufild, David A.; Green, Sheldon

1994-01-01

435

77 FR 55863 - NASA Advisory Council; Science Committee; Earth Science Subcommittee; Applied Sciences Advisory...  

Federal Register 2010, 2011, 2012, 2013

...Advisory Council; Science Committee; Earth Science Subcommittee; Applied Sciences...Group. This Subcommittee reports to the Earth Science Subcommittee Committee of the NASA...Applied Sciences Program Update --Earth Science Data Latency Study...

2012-09-11

436

Science and Engineering Indicators: 1993  

NSF Publications Database

Science & Science & Engineering Indicators '93 provides a comprehensive overview of the science ... The hypertext version of the Science & Engineering Indicators '93 was developed under contract to ...

437

Excitement in shame: the price we pay.  

PubMed

This paper explores the role of excitement in shame, extending the theoretical underpinnings of my work (Aledort, 2002, 2003, 2008, 2009) on narcissism and the omnipotent child syndrome. Shame, excitement, and early narcissistic self-states are complexly intermingled, each influencing the other. Empathy alone is insufficient; the passion connected to shame can be easily hidden. Detailed case studies describe a model for working with the excitement in shame, how it functions, and how it gets resolved. PMID:24320576

Aledort, Stewart L

2014-01-01

438

Hybrid Excitation of the Axial Inductor Machine  

NASA Astrophysics Data System (ADS)

The paper considers the possibility to use permanent magnets in the rotor slots of axial inductor machine with the aim to create a hybrid excitation of such a machine - from the magnets and from the excitation winding which is placed between the stator cores. The hybrid excitation allows the weight and size parameters of the machine to be improved. Under consideration is a 32 kW under-carriage generator 2?B.13.Y1.

Orlova, S.; Pugachov, V.; Levin, N.

2012-01-01

439

Periodic acceptor excitation spectroscopy of single molecules  

PubMed Central

Alternating-laser excitation (ALEX) spectroscopy has recently been added to the single-molecule spectroscopy toolkit. ALEX monitors interaction and stoichiometry of biomolecules, reports on biomolecular structure by measuring accurate Förster resonance energy transfer (FRET) efficiencies, and allows sorting of subpopulations on the basis of stoichiometry and FRET. Here, we demonstrate that a simple combination of one continuous-wave donor-excitation laser and one directly modulated acceptor-excitation laser (Periodic Acceptor eXcitation) is sufficient to recapitulate the capabilities of ALEX while minimizing the cost and complexity associated with use of modulation techniques.

Doose, Soren; Heilemann, Mike; Michalet, Xavier; Weiss, Shimon

2011-01-01

440

Rydberg excitation of Bose-Einstein condensates.  

PubMed

Rydberg atoms provide a wide range of possibilities to tailor interactions in a quantum gas. Here, we report on Rydberg excitation of Bose-Einstein condensed 87Rb atoms. The Rydberg fraction was investigated for various excitation times and temperatures above and below the condensation temperature. The excitation is locally blocked by the van der Waals interaction between Rydberg atoms to a density-dependent limit. Therefore, the abrupt change of the thermal atomic density distribution to the characteristic bimodal distribution upon condensation could be observed in the Rydberg fraction. The observed features are reproduced by a simulation based on local collective Rydberg excitations. PMID:18232977

Heidemann, Rolf; Raitzsch, Ulrich; Bendkowsky, Vera; Butscher, Björn; Löw, Robert; Pfau, Tilman

2008-01-25

441

New excitation method of surface polaritons  

NASA Astrophysics Data System (ADS)

A new excitation method is proposed for surface polaritons of an evanescent mode which cannot be excited by the attenuated total reflection method. A thin-film waveguide has been designed and produced to excite surface polaritons of evanescent modes at a Ag-SiO2 interface. If the wave number of the optical guided waves propagating in the dielectric thin-film waveguide (SiO2/Ta2O5/SiO2) is equal to the wave number of the surface polaritons, then a coupling between the two modes occurs. The excitation of the surface polaritons can be confirmed by an attenuation of the optical guided waves.

Nakagawa, Yasuhiko; Kaneko, Michihiro; Terunuma, Noboru

1988-11-01

442

Water Science School  

MedlinePLUS

The USGS Water Science School The USGS Water Science School Welcome to the U.S. Geological Survey's ( USGS ) Water Science School. We offer information on many aspects of water, along with pictures, ...

443

Report: Mathematics and Science  

NSF Publications Database

Donald J. Lewis Director (1995-1999) Division of Mathematical Science National Science Foundation Mathematics and Science Contents...............................................................2 Overview...............................................................3 Themes.................................................................3 Modeling...............................................................3 Complexity and Size....................................................4 ...

444

CONTAMINATED SEDIMENTS SCIENCE PRIORITIES  

EPA Science Inventory

The Contaminated Sediment Science Priorities (CSSP) document isa mechanism for the U.S. EPA to develop and coordinate Agency-wide science activities that affect contaminated sediments. It analyzes current Agency contaminated sediments science activities, identifies and evaluates...

445

Women "and" Science.  

ERIC Educational Resources Information Center

Science and medicine are littered with the images of men. Introduces an interdisciplinary course devoted to the subject of women, gender, and science issues. Discusses possible ways to encourage females to pursue careers in science. (Contains web resources.) (YDS)

Galupo, M. Paz; Gasparich, Gail E.

2000-01-01

446

Science, Values and Objectivity.  

ERIC Educational Resources Information Center

Attempts to ascertain whether the presence of biasing values in the practice of science is an inbuilt feature of an idealized institution, Science, and judges that those values inbuilt to Science are not a source of bias. (Author/MM)

Davson-Galle, Peter

2002-01-01

447

Science Education at AAAS  

ERIC Educational Resources Information Center

Describes several programs of the American Association for the Advancement of Science (AAAS) Office of Science Education (OSE), including short courses offered in the natural and social sciences, mathematics, and engineering to college teachers. Discusses several OSE publications. (MLH)

Livermore, Arthur H.

1975-01-01

448

National Science Resources Center  

NSDL National Science Digital Library

The NSRC collects and disseminates information about exemplary science teaching resources, develops innovative science curriculum materials, and sponsors outreach activities to help school districts develop and sustain hands-on science programs.

Center, National S.

2003-10-10

449

Security Science as an Applied Science?  

ERIC Educational Resources Information Center

Describes the development of a security science degree as the emerging applied science of the protection of individuals and assets. Proposes the themes of physical, electronic, information security and facility management as scientific applications for the course. (Author/MM)

Smith, Clifton

2001-01-01

450

Applications of Nuclear Science for Stewardship Science  

NASA Astrophysics Data System (ADS)

Stewardship science is research important to national security interests that include stockpile stewardship science, homeland security, nuclear forensics, and non-proliferation. To help address challenges in stewardship science and workforce development, the Stewardship Science Academic Alliances (SSAA) was inaugurated ten years ago by the National Nuclear Security Administration of the U. S. Department of Energy. The goal was to enhance connections between NNSA laboratories and the activities of university scientists and their students in research areas important to NNSA, including low-energy nuclear science. This paper presents an overview of recent research in low-energy nuclear science supported by the Stewardship Science Academic Alliances and the applications of this research to stewardship science.

Cizewski, Jolie A.

2013-03-01

451

Understanding Science: Misconceptions About Science  

NSDL National Science Digital Library

This web page explores misinterpretations of the scientific process and explains why these commonly-held beliefs are incorrect. A few examples of such misconceptions are: "Without an experiment, a study is not rigorous or scientific"; "There is a single scientific method that all scientists follow"; "Scientific ideas are absolute"; "The job of a scientist is to find support for his/her hypothesis"; "Investigations that don't reach a firm conclusion are useless." The authors also clarify vocabulary mix-ups that occur when lay language and scientific language use the same words differently (such as "uncertainty", "law", and "error"). This web page is part of the Understanding Science project developed by the University of California Museum of Paleontology, in collaboration with a diverse group of scientists and teachers.

2010-09-29

452

Team Science Toolkit  

Cancer.gov

My work in the science of team science (SciTS) field has focused on developing and supporting the SciTS field, conducting studies that aim to further elucidate the processes and outcomes of team science through multi-method approaches, and advancing methods, measures, models for evaluating team science broadly and transdisciplinary team science collaborations specifically. Additionally, I work to develop tools to facilitate and mechanisms to support the conduct of transdisciplinary team science.

453

California Science Explorer Transparencies  

NSDL National Science Digital Library

This collection of transparencies features materials for life science, earth science, and physical sciences. The transparencies are downloadable and printable, or can be viewed on-screen. Earth Science topics include plate tectonics and the Earth's structure; landforms and weathering; water, hydrology, and weather; and ecosystems and food webs. Life science topics include, among others, evolution and the Earth's history, and structure and function in living things. Physical science topics include motion, forces, and energy; sound and light; and electricity and magnetism.

454

Visions of Inquiry: Science  

NSDL National Science Digital Library

This chapter first looks at how science inquiry is viewed in the National Science Education Standards (NRC 1996). It then briefly describes some historical attempts to make science inquiry an important part of school science, discusses images of science inquiry, and concludes with a commentary on the relationships between science inquiry as literacy of the phenomenon on the one hand and literacy of the spoken and written word on the other.

Dyasi, Hubert M.

2006-01-01

455

The Science Club  

NSDL National Science Digital Library

The Science Club's website lists various science sites and projects that are good for K-12 students. Since 1987, The Science Club has been bringing science to life for over one million elementary school children, teachers, and parents. The Science Club fuels the wonder and joy of learning, through school assemblies, parent and teacher workshops, television, video, and print. The Science Club has also designed programs for museums, agencies, and educational organizations.

Beaty, Bill

2013-06-10

456

SIMPLE Science - Earth and Space Science Home  

NSDL National Science Digital Library

The Simplified Image Management and Processing Learning Environment for Science (SIMPLE Science) aims to create resources for middle school that emphasize image processing and analysis techniques while at the same time meet educational standards. The collection features tutorials that (a)guide students through case studies replicating research conducted by leading imaging scientists and (b)explain key concepts in imaging science. This is the entry for the Earth and space science section.

457

Science Made Simple: Science fair projects  

NSDL National Science Digital Library

This resource provides science projects and experiments that use common household materials to explain why the sky is blue, why leaves change colors, what static electricity is, and how animals hibernate. There is a section on current science news and a tool for online measurement conversions. A newsletter is available by subscription that provides science information for teachers and parents ten times per year.

458

Hands-On Science. Journals of Science.  

ERIC Educational Resources Information Center

Describes how to use journal writing in elementary science classes. Writing lets children communicate observations and ideas while reinforcing understanding of key science concepts. Journal ideas include using notebooks to respond to teacher prompts or write about what students are studying; sharing a classroom science journal; and keeping a…

Kepler, Lynne

1998-01-01

459

The Science(s) of Adult Education.  

ERIC Educational Resources Information Center

Using criteria to determine whether a discipline is a science, the author defines andragogy as a technological discipline that applies principles discovered by the sciences of adult education--educational psychology, sociology, economics, and anthropology. He suggests that andragogy could become the general science of adult education by studying…

Pastuovic, Nikola

1995-01-01

460

Common Earth Science Misconceptions in Science Teaching  

ERIC Educational Resources Information Center

A survey of the Earth science content of science textbooks found a wide range of misconceptions. These are discussed in this article with reference to the published literature on Earth science misconceptions. Most misconceptions occurred in the "sedimentary rocks and processes" and "Earth's structure and plate tectonics" categories; the most…

King, Chris

2012-01-01

461

Putting Science into Elementary Science Fairs.  

ERIC Educational Resources Information Center

In a world where science has become too confined to books and too reliant on technology, and science fairs have been taken over by parents, this paper offers suggestions to help young people have actual hands-on experience with nature. Topics include soil formation; ants; earthworms; temperature; weather predictions; rain acidity; physical science

Russell, Helen Ross

462

Newspaper science, school science: friends or enemies?  

Microsoft Academic Search

Learning through newspapers is considered an instance of informal science learning ? an area of learning which is notoriously difficult to assess, and its relationship with formal learning hard to unravel. It is argued that the science presented in newspapers can be of value in formal science education if used carefully and critically. From the other perspective, it is suggested

J. Wellington

1991-01-01

463

Normal Science, Pathological Science and Psychometrics  

Microsoft Academic Search

A pathology of science is defined as a two-level breakdown in processes of critical inquiry: first, a hypothesis is accepted without serious attempts being made to test it; and, second, this first-level failure is ignored. Implications of this concept of pathology of science for the Kuhnian concept of normal science are explored. It is then shown that the hypothesis upon

Joel Michell

2000-01-01

464

CONPTT: Science vs. Non-Science  

NSDL National Science Digital Library

This lesson explores six criteria of science (Consistent, Observable, Natural, Predictable, Testable, and Tentative (CONPTT)), with definitions and self-check questions. It compares emerging science, non-science, and pseudoscience, with definitions and examples. The activity engages students in analyzing a collection of paragraphs to decide which category each fits into.

Dickhaus, Steven

465

Science enrichment through informal science. Final report.  

National Technical Information Service (NTIS)

Hands On Science Outreach (HOSO) is a program of informal science education. Its mission is to bring to communities the option of out-of-school science explorations to small groups of children from the ages of 4-12. Such experiences encourage children to ...

P. Katz

1996-01-01

466

The Science Club: Kids' Science Projects  

NSDL National Science Digital Library

This collection of science projects covers electricity and magnets, optics, and other physical science topics. The projects are arranged by simple, medium, and advanced skill levels, and include videos that show the materials used and how the experiment is performed. There are also links to other science project websites and to sites where materials for the projects may be purchased.

Beaty, William J.

467

Girls in Science Rule!  

NSDL National Science Digital Library

This overnight camp for girls provided opportunity for outdoor adventures while building science process skills and interest in science careers. Students participated in activities relating to ecology.

Moore, Jan E.

2003-04-01

468

The Space Science Group  

NSDL National Science Digital Library

The Space Science Group is part of the Division of Mathematics and Sciences at Northwestern State University in Natchitoches, La. The mission of The Space Science Group is to provide activities that encourage participation in math and science, build knowledge of basic concepts, teach basic science skill, and positively influence attitudes. The mission of The Space Science Group is to develop and implement programs which use aspects of the space program to motivate students to study mathematics and science. Many Space Science Group programs are described at the URL below.

1997-01-01

469

Fusion energy science: Clean, safe, and abundant energy through innovative science and technology  

SciTech Connect

Fusion energy science combines the study of the behavior of plasmas--the state of matter that forms 99% of the visible universe--with a vision of using fusion--the energy source of the stars--to create an affordable, plentiful, and environmentally benign energy source for humankind. The dual nature of fusion energy science provides an unfolding panorama of exciting intellectual challenge and a promise of an attractive energy source for generations to come. The goal of this report is a comprehensive understanding of plasma behavior leading to an affordable and attractive fusion energy source.

None

2001-01-01

470

DASH: Developmental Approaches in Science, Health and Technology: Kindergarten. Teacher Guide.  

ERIC Educational Resources Information Center

The goal of the Developmental Approaches in Science, Health and Technology (DASH) program is to preserve the curiosity and capture the imagination of all elementary students through an experience of science, technology, and health that engages them in the excitement of exploring and understanding the unknown, inventing and building to solve…

Pottenger, Francis M., III; Brennan, Carol Ann; Pottenger, Larma M.

471

Keynote Lecture: Basic Science and the NIH: American Society for Cell Biology Meeting  

Cancer.gov

Let me tell you briefly how it happened. Just a few years ago, my interests in the politics of science were barely noticeable. Like most of you, I was reasonably content, and often very happy, to be doing science in this remarkably exciting era in biology. Then, seemingly all at once, a number of things happened.

472

A Flexible Database-Centric Platform for Citizen Science Data Capture  

Microsoft Academic Search

The paper describes a platform developed by the Extreme Citizen Science (ExCiteS) group at University College London over the past five years to facilitate online data capture by Citizen Scientists in the context of community science, where local environmental problems are monitored. Responding to user needs, the platform has been developed to be as flexible as possible in terms of

Claire Ellul; Louise Francis

2011-01-01

473

Looking through the Lenses of Science Literacy and Cultural Diversity: Learning from Helena's Mistake  

ERIC Educational Resources Information Center

Maria Andree focuses on an immigrant student whose error in a laboratory activity leads to a novel, colorful outcome that she excitedly shares with peers. After engaging in class activities for a few weeks she returns to her earlier dislike of science, saying: "I hate science, particularly Chemistry." The classroom activity system focused on…

Chinn, Pauline W. U.

2012-01-01

474

Vibrationally Excited Molecular Hydrogen near Herschel 36  

NASA Astrophysics Data System (ADS)

We present the first high resolution UV spectra toward Herschel 36, a Trapezium-like system of high-mass stars contained within the Lagoon Nebula (M8, NGC 6523). The spectra reveal extreme rovibrational excitation of molecular hydrogen in material at a single velocity or very small range of velocities, with this component presumably lying near the star system and undergoing fluorescent excitation. The overall H2 excitation is similar to, but apparently larger than, that seen toward HD 37903 which previously showed the largest vibrationally excited H2 column densities seen in UV absorption spectra. While the velocities of the highly excited H2 lines are consistent within each observation, it appears that they underwent a ~60 km s-1 redshift during the 3.6 yr between observations. In neither case does the velocity of the highly excited material match the velocity of the bulk of the line-of-sight material which appears to mostly be in the foreground of M8. Recent work shows unusually excited CH and CH+ lines and several unusually broad diffuse interstellar bands toward Herschel 36. Along with the H2 excitation, all of these findings appear to be related to the extreme environment within ~0.1 pc of the massive young stellar system.

Rachford, Brian L.; Snow, Theodore P.; Ross, Teresa L.

2014-05-01

475

Laser-excited synchronous luminescence spectroscopy  

Microsoft Academic Search

The use of lasers as excitation sources for molecular luminescence often results in improvements in sensitivity and limits of detection (LODs). Synchronous luminescence (SL) spectroscopy, in which both excitation and emission wavelengths are scanned simultaneously, provides a convenient means to improve selectivity (often dramatically) in the analysis of multicomponent mixtures using room-temperature luminescence. The authors report here on the first

Christopher L. Stevenson; Tuan Vo-Dinh

1993-01-01

476

Invasion Waves in Populations with Excitable Dynamics  

Microsoft Academic Search

Whilst the most obvious mechanism for a biological invasion is the occupation of a new territory as a result of direct ingress by individuals of the invading population, a more subtle “invasion” may occur without significant motion of invading individuals if the population dynamics in a predator prey scenario has an “excitable” character. Here, “excitable” means that a local equilibrium

J. Brindley; V. H. Biktashev; M. A. Tsyganov

2005-01-01

477

Excited hadrons on the lattice: Mesons  

SciTech Connect

We present results for masses of excited mesons from quenched calculations using chirally improved quarks at pion masses down to 350 MeV. The key features of our analysis are the use of a matrix of correlators from various source and sink operators and a basis which includes quark sources with different spatial widths, thereby improving overlap with states exhibiting radial excitations.

Burch, Tommy; Hagen, Christian; Schaefer, Andreas [Institut fuer Theoretische Physik, Universitaet Regensburg, D-93040 Regensburg (Germany); Gattringer, Christof; Glozman, Leonid Ya.; Lang, C.B. [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria)

2006-05-01

478

Plasma wakefield excitation by charge particle beams  

Microsoft Academic Search

Electron plasma waves excited by a charge bunch are studied analytically and via computer simulations in full generality. Analytic results of plasma wakefield excitation are compared with particle-in-cell computer simulations both qualitatively and quantitatively. Doppler shifts and the nonlinear properties of plasma waves are included. One of the major goals is to study plasma applications to high energy physics. Accelerator

Jao-Jang Su; Jaojang

1990-01-01

479

Configurational statistics of excited granular materials  

Microsoft Academic Search

In this dissertation, we investigate theories of configurational statistics for excited granular materials, and test the predictions with extensive molecular dynamics (MD) simulations. First we examine a system of weakly excited granular materials in a vibrating bed. We use a thermodynamic theory of hard spheres, which explores consequences of the excluded volume interaction under gravity. The global temperature T, is

Paul Victor Quinn

2001-01-01

480

The excited random walk in one dimension  

Microsoft Academic Search

We study the excited random walk, in which a walk that is at a site that contains cookies eats one cookie and then hops to the right with probability p and to the left with probability q = 1 - p. If the walk hops onto an empty site, there is no bias. For the 1-excited walk on the half-line

Tibor Antal; S. Redner

2005-01-01